WO2016195559A1

WO2016195559A1 - Changing the acoustic performance of a sound emitting device

Info

Publication number: WO2016195559A1
Application number: PCT/SE2015/050655
Authority: WO
Inventors: Matthew John LAWRENSON; Julian Charles Nolan; Jacob STRÖM
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2015-06-05
Filing date: 2015-06-05
Publication date: 2016-12-08
Anticipated expiration: 2017-12-05

Abstract

A method for changing the acoustic performance of a sound emitting device is provided. The method comprises emitting (110) audible sound using at least one loudspeaker of the sound emitting device; capturing (120) the emitted audible sound using a microphone arrangement of the sound emitting device; and evaluating (130) the acoustic performance of the sound emitting device based on the captured audible sound and the emitted audible sound. The method further comprises changing (140) the shape of the sound emitting device based on the evaluated acoustic performance.

Description

CHANGING THE ACOUSTIC PERFORMANCE OF A SOUND EMITTING

DEVICE

Technical field

[0001 ] The present disclosure relates to a sound emitting device, a method performed by a sound emitting device, and corresponding computer program and computer program products.

Background

[0002] The acoustic output (audible sound) of a device may be modified by external surfaces in close proximity to the device's speakers. Depending on the surface and/or user preference the sound could be thought of as being either improved or degraded by the modification.

[0003] With regard to the use of filtering and amplification of various frequency bands - such techniques are limited by the ability of the overall system. For example, if the system's speakers are not able to deliver the required power at a certain frequency, then the electronic modifications to the audio signal will not be have the desired effect. Also, the available range of electronic modification may not be sufficient to modify the sound to the required level. For example, if a smartphone has been placed such that the speaker is blocked by an object, the system may not be able to adjust sufficiently, whereas if the smartphone was able to change shape or move the speaker, the blockage could be removed.

Summary

[0004] The object of the invention is to obviate at least some of the problems outlined above. In particular, it is an object of the invention to provide a sound emitting device, and a method performed by the sound emitting device, for changing its acoustic performance. These objects and others are obtained by the sound emitting device, and the method performed by a sound emitting device, according to the independent claims. [0005] According to a first aspect of the invention, a method performed by a sound emitting device for changing its acoustic performance is provided. The sound emitting device comprises, or is connectable to, a microphone arrangement and comprises at least one loudspeaker. The sound emitting device is further operable to assume at least two different shapes. The method comprises emitting audible sound using the at least one loudspeaker, capturing the emitted audible sound using the microphone arrangement, and evaluating the acoustic

performance of the sound emitting device based on the captured audible sound and the emitted audible sound. The method further comprises changing the shape of the sound emitting device based on the evaluated acoustic performance.

[0006] According to a second aspect of the invention, a sound emitting device configured for changing its acoustic performance is provided. The sound emitting device comprises, or is connectable to, a microphone arrangement and comprises at least one loudspeaker. The sound emitting device is further operable to assume at least two different shapes. The sound emitting device is configured for emitting audible sound using the at least one loudspeaker, capturing the emitted audible sound using the microphone arrangement, and evaluating the acoustic

performance of the sound emitting device based on the captured audible sound and the emitted audible sound. The sound emitting device is further configured for changing the shape of the sound emitting device based on the evaluated acoustic performance.

[0007] According to a third aspect of the invention, a computer program comprising computer readable instructions is provided. When run in a processing unit comprised in a sound emitting device, the computer readable instructions cause the sound emitting device to perform the method according to the first aspect of the invention.

[0008] According to a fourth aspect of the invention, a computer program product is provided. The computer program product comprises the computer program according to te third aspect of the invention. [0009] The method performed by the sound emitting device, and the sound emitting device itself, have several advantages. One advantage is that a degradation of the emitted audible sound due to the surroundings of the sound emitting device may be reduced or totally overcome. Another advantage is that specific sound characteristics may be achieved by assuming a shape of the device that supports those specific sound characteristics.

Brief description of drawings

[00010] Embodiments will now be described in more detail in relation to the accompanying drawings, in which:

[0001 1 ] Figure 1 is a flowchart of a method performed by a sound emitting device, according to an embodiment of the invention.

[00012] Figure 2a is an illustration of examples of different shapes an

embodiment of the sound emitting device may assume.

[00013] Figure 2b is an illustration of a further example of different shapes an embodiment of the sound emitting device may assume.

[00014] Figure 3 is a block diagram of a sound emitting device, according to an embodiment of the invention.

[00015] Figure 4 is a block diagram of a sound emitting device, according to another embodiment of the invention.

[00016] Figure 5 is a block diagram of an arrangement in a sound emitting device, according to an embodiment of the invention.

Detailed description

[00017] A sound emitting device and a method performed by the sound emitting device for changing its acoustic performance are provided. By capturing audible sound emitted from the sound emitting device and evaluating the captured audible sound, the sound emitting device may evaluate how the emitted audible sound is affected by the surroundings of the sound emitting device. In order to change its acoustic performance, the sound emitting device changes its shape in order to change the spatial relationship between at least one loudspeaker of the device and the surroundings (e.g., a table upon which the device is laying or an object which is close to the device), thereby also changing its acoustic performance.

[00018] Embodiments described herein relate to a method performed by a sound emitting device for changing its acoustic performance. Embodiments of such a method will now be described with reference to figure 1. The sound emitting device comprises, or is connectable to, a microphone arrangement and comprises at least one loudspeaker. The sound emitting device is further operable to assume at least two different shapes. Figure 1 illustrates the method comprising emitting 1 10 audible sound using the at least one loudspeaker, capturing 120 the emitted audible sound using the microphone arrangement, and evaluating 130 the acoustic performance of the sound emitting device based on the captured audible sound and the emitted audible sound. The method further comprises changing 140 the shape of the sound emitting device based on the evaluated acoustic

performance.

[00019] The sound emitting device emits the audible sound, which may be a tone, part of a song or melody, noise, in particular pink or white noise, or any other type of audible sound. Emitting the audible sound is effected by providing an electric signal to the loudspeaker. Assuming that the loudspeaker is "perfect", the emitted audible sound correspond perfectly to the electric signal. However, in reality, the loudspeaker may distort the electric signal such that it is affected by the characteristics of the loudspeaker. This distortion may result in the frequency spectrum of an emitted audible sound being different from the frequency spectrum of the electric signal representing the audible sound.

[00020] As the audible sound is emitted, it is affected by the surroundings of the device. Merely as an example, if the sound emitting device is laying on a hard table and the loudspeaker, or at least one of the loudspeakers, is arranged in the sound emitting device such that it is more or less adjacent to the table or emits sound in the direction of the table, the emitted audible sound is affected by the table. If instead the same sound emitting device is laying on a soft piece of cloth (e.g., if there is a thick table cloth on the table), the sound is affected by the cloth in a different manner. As another example, one may consider a sound emitting device which is a smartphone or has the shape of a smartphone, and that the screen comprises the at least one loudspeaker. When the sound emitting device is laying on a surface with the loudspeaker/screen facing up, the emitted sound will not be severely affected by the material upon which the sound emitting device is laying. However, should the loudspeaker/screen be facing the surface on which the sound emitting device is laying, the sound will be muffled, but probably differently depending in the material of the surface upon which the sound emitting device is laying.

[00021 ] Once the audible sound is emitted, it is captured by the microphone arrangement. The microphone arrangement may be comprised in the sound emitting device or it may connected to the sound emitting device and may thus be located at a distance from the sound emitting device. The microphone

arrangement captures the audible sound as it is affected by the surroundings of the sound emitting device. As briefly described above, the captured audible sound may be different from the emitted audible sound due to the surroundings of the device. In other words, depending on the surroundings, the emitted audible sound may be affected in different ways and to different degree.

[00022] The sound emitting device then evaluates its acoustic performance based on the captured audible sound and the emitted audible sound. By comparing the emitted audible sound and the captured audible sound, the sound emitting device obtains information of how and to what degree the audible sound is affected by its surroundings, as will be explained in more detail below.

[00023] Once the sound emitting device has evaluated how and to what degree the audible sound is affected by its surroundings, the sound emitting device may change its shape based on the evaluation. By changing the shape, the sound emitting device may change, e.g., the distance between the at least one loudspeaker and objects in its surroundings, as well as their relative orientation. By changing the shape, the sound emitting device may, e.g., create or increase a distance between the at least one loudspeaker and the closest surface. Reverting to the examples described above, if the sound emitting device is a smartphone or has the shape of a smartphone having the at least one loudspeaker arranged at an edge of the smartphone, and the smartphone is laying on a tablecloth such that the at least one loudspeaker is very close to the table or is "pointing" or emitting sound towards the table, the sound may be quite severely muffled by the tablecloth. The sound emitting device may then change shape such that the end or edge of the sound emitting device where the at least one loudspeaker is arranged is lifted from the surface, i.e., the tablecloth, wherein the emitted audible sound may be less affected (muffled). It shall be pointed out that this is merely an example and different shapes and how they may be changed will be described in more detail below.

[00024] The method performed by the sound emitting device has several advantages. One possible advantage is that a degradation of the emitted audible sound due to the surroundings of the sound emitting device may be reduced or totally overcome. Another advantage is that specific sound characteristics may be achieved by assuming a shape of the device that supports those specific sound characteristics.

[00025] As briefly described above, the microphone arrangement may be comprised in the sound emitting device, or may be connected to the sound emitting device. For example, if the sound emitting device is a wireless

communication device, such as a smartphone or the like, it most likely will comprise at least one microphone.

[00026] However, the microphone arrangement may alternatively be connectable to the sound emitting device, e.g., if the microphone arrangement is a headset or a stand-alone microphone. [00027] Evaluating 130 the acoustic performance may be based on a respective representation of the emitted audible sound and the captured audible sound.

[00028] There may be different ways of representing the emitted audible sound and the captured audible sound. One example is by means of a parametric representation. There are different examples of parametric representation, e.g., parametric representation of temporal relations or changes of the audible sound, and parametric representation of spatial audio of the audible sound. Another example of parametric representation is based on wavelength and/or frequency. The emitted audible sound may comprise a plurality of different wavelengths, which may be affected differently due to the surroundings of the sound emitting device. Some wavelengths may be attenuated to larger extent and some may be left relatively unaffected by the surroundings. The different wavelengths may be represented by parameters, i.e., the different wavelengths or wavelength ranges of the emitted audible sound may be represented by a parameterisation of the emitted audible sound and the different wavelengths or wavelength ranges of the captured audible sound may be represented by a parameterisation of the captured audible sound. The parameterisation of the emitted audible sound and the parameterisation of the captured audible sound are preferably performed using the same method. The respective parametric representation of the emitted and the captured audible sound indicates the different wavelengths or wavelength ranges and their respective amplitudes.

[00029] The sound emitting device may then, when evaluating 130 its acoustic performance, compare the amplitudes of the different wavelengths or wavelength ranges of the emitted audible sound with the amplitudes of corresponding wavelengths or wavelength ranges of the captured audible sound. That is, by comparing the parameterisation of the emitted audible sound with the

parameterisation of the captured audible sound, the sound emitting device may determine how the surroundings have affected the emitted audible sound.

[00030] As an example, evaluating 130 the acoustic performance may comprise comparing a representation of the captured audible sound with one or more preferences, and changing 140 the shape of the sound emitting device if the captured audible sound deviates at least to a predetermined extent from the one or more preferences. This is advantageous if audible sound with a frequency spectrum known to the device is emitted, such as white or pink noise.

[00031 ] As described above, the representation may be a parametric

representation representing different wavelengths or wavelength ranges of the emitted audible sound and the captured audible sound, respectively. Thus, the sound emitting device has information about a parametric representation of the emitted audible sound. In addition to comparing the parametric representation of the captured audible sound to the parametric representation of the emitted audible sound, the sound emitting device may also make use of one or more preferences. The one or more preferences may, e.g., be related to preferences of a user of the sound emitting device or may be related to different types of audible sound, e.g., speech, music, or the like.

[00032] The sound emitting device may also compare the captured audible sound with the one or more preferences, e.g., by comparing respective parametric representations thereof, in order to change the shape of the sound emitting device. The one or more preferences may comprise user preferences or factory-set preferences. The preferences may be in the form of parameters, thresholds, frequency spectra (in particular for evaluating emitted white/pink noise), deviation from the frequency spectrum of the emitted sound, and so on.

[00033] Instead of having exact or fixed values of different parameters of the different representations, the different parameters of the one or more preferences may be associated with a respective interval. In this manner, each parameter, e.g., the amplitude of a certain wavelength, may vary within an interval. Different parameters may have different intervals. For instance, the one or more

preferences may define a range for a parameter A, e.g., the amplitude or acoustic power of a certain wavelength or wavelength range, such that A may vary between a lower threshold a_min and an upper threshold a_max. [00034] The method may further comprise deriving an acoustic model

representing the surrounding of the sound emitting device based on the captured audible sound and/or the evaluated acoustic performance. As described above, the surrounding may affect different wavelengths of the emitted audible sound in different ways. The acoustic model provides information of how different wavelengths of the emitted audible sound are affected by the surroundings of the sound emitting device. The shape of the sound emitting device may be changed based on the acoustic model.

[00035] Once the sound emitting device has derived the acoustic model, it may use the acoustic model to obtain information and knowledge of how different wavelengths of the emitted audible sound are affected by the surroundings of the sound emitting device. Merely as an example, wavelengths of base tones, having relatively long wavelengths, may be affected very differently by the surroundings than wavelengths of high tones, having relatively short wavelengths.

[00036] Based on the acoustic model, the sound emitting device may deduce information pertaining to how different wavelengths are affected whereas some wavelengths may remain relatively unaffected by the surroundings. Using this information provided by the acoustic model, the sound emitting device may change its shape in order to overcome or reduce the impact the surroundings have on different wavelengths.

[00037] The method may further comprise emitting further audible sound, capturing the emitted further audible sound, evaluating the further captured emitted audible sound, and changing the shape based on a comparison of the acoustic performance evaluated for the audible sound and the acoustic

performance evaluated for the further emitted audible sound.

[00038] By emitting the further audible sound after the new shape has been assumed by the sound emitting device, the sound emitting device may determine if the new shape provides satisfactorily acoustic performance or if yet another shape should be assumed. The further audible sound may be the same audible sound as previously emitted or it may be a new (different) audible sound.

[00039] The sound emitting device then captures the emitted further audible sound and evaluates the captured further audible sound in the same manner as described above. When the sound emitting device selects a new shape to assume, i.e., changes the shape, it bases the selection of shape on both the latest evaluation for the emitted further audible sound and on the previous one or more evaluations.

[00040] In this manner, the sound emitting device attempts to find the shape that most likely provides the best acoustic performance given the surroundings of the sound emitting device.

[00041 ] As an example, changing 140 the shape of the sound emitting device further comprises, when a plurality of shapes have been evaluated by the sound emitting device, determining which of the assumed shapes best matches one or more preferences, and changing to that shape.

[00042] It may be that the sound emitting device has assumed several different shapes without finding a shape for which the acoustic performance is considered satisfactory. In other words, the sound emitting device may have assumed several different shapes, emitted audible sound, captured the emitted audible sound, and evaluated its acoustic performance, without finding a shape fulfilling one or more preferences or requirements as described above.

[00043] The sound emitting device may store previous performed evaluations of emitted audible sound(s) and respective shapes of the sound emitting device during those previous performed evaluations.

[00044] The different shapes may have resulted in acoustic performances which deviate to different extent from a desired acoustic performance, as defined by the one or more preferences. As an example, assuming that parameters A, B, and C, of the captured emitted audible sound should have values a, b, and, c respectively, in order for the acoustic performance to be deemed acceptable, the situation may occur that none of the assumed shapes has fulfilled those

requirements. For instance, for a first shape S1 , none of the parameters A, B, and, C were even close to the values a, b, and c, respectively. For a second shape S2, parameter A had a value close to a, but the values for parameters B and C were far from the desired values b and c, respectively. For a third shape S3, parameter A had a value close to a, and parameter B had a value close to b, but the value of parameter C was far from c. In this case, whereas none of the shapes S1 , S2, and S3, fulfil the requirements defining satisfactory acoustic performance, shape S3 is the shape which matches the requirements best and may be considered the best of the assumed shapes. Accordingly, the sound emitting device may then assume shape S3. By determining which of the assumed shapes best matches one or more preferences, the sound emitting device may select the best shape possible and then change to that shape.

[00045] There are many different ways in which the sound emitting device may change its shape. In an example, the shape of the sound emitting device is changed by means of at least one actuator.

[00046] The at least one actuator could for example be a rod that may be changed from a first position wherein it is aligned with the sound emitting device to a second position wherein it protrudes from the sound emitting device. For example, if the sound emitting device may have the shape of a smartphone, which is relatively thin, having the rod arranged at an edge of the backside of the sound emitting device. When the rod is aligned with the sound emitting device, the sound emitting device may lay flat on a surface. When the rod protrudes from the sound emitting device, it lifts a corner or an edge of the sound emitting device, thereby possible changing the distance between the at least one loudspeaker and the surface upon which the sound emitting device is laying.

[00047] Another example of the at least one actuator is a micro actuator, wherein the sound emitting device comprises flexible electronics mounted on flexible substrates, wherein the micro actuator(s) may bend the sound emitting device. [00048] More examples will be given and described below with reference to figures 2a and 2b.

[00049] In another example, the shape of the sound emitting device is changed by means of a motor.

[00050] Also for the motor there may be many different examples. One example is that the sound emitting device comprises two parts being connected or coupled together by a hinge arrangement around which the two parts are rotatable. The sound emitting device may comprise a motor which may rotate the two parts around the hinge arrangement, thereby changing the shape of the sound emitting device.

[00051 ] In yet another example, wherein the sound emitting device comprises at least two parts having different thermal expansion coefficients, the shape of the sound emitting device may be changed by changing a temperature of the at least two parts of the device. Since the at least to parts expand differently in response to the temperature change, the shape of the sound emitting device is changed.

[00052] In this example, the sound emitting device comprises at least one material which has a comparatively large thermal expansion coefficient as compared to another material of the sound emitting device. Generally, the sound emitting device comprises a plurality of different components and materials, all having different characteristics. However, one of these different materials has a comparatively large thermal expansion coefficient as compared to at least one other material, wherein heating or cooling of that material may cause the sound emitting device to change its due to the material expanding or contracting.

[00053] Alternatively, changing 140 the shape of the sound emitting device may comprise at least one of (i) pumping air into, or letting air out of, an expandable chamber of the device, and (ii) pumping liquid into, or letting liquid out of, the expandable chamber. [00054] The sound emitting device may comprise an expandable chamber into which air or liquid may be pumped into or let out of. Merely as an example, assume the sound emitting device has at least one flat part, facing a table on which the sound emitting device is laying. On this flat part, an expandable chamber is arranged, wherein the flat part is flat when there is no air or liquid present in the expandable chamber. By pumping air or liquid into the chamber, at least a part of the previously flat part may be bulging out from the previously flat part thereby raising at least a part of the sound emitting device relative to the surface on which the sound emitting device is laying.

[00055] In the following, the sound emitting device will be exemplified as a smartphone. It shall be pointed out that the sound emitting device is not limited to being a smartphone, it may be an MP3 player, a Personal Digital Assistant (PDA) having audio emitting capabilities, a tablet, a loudspeaker accessory, etc.

[00056] Modern smartphones typically include the ability to emit audio, for the purpose of entertainment (playing music, films etc.), speech interfaces, and notifications. The placement of a traditional speaker is somewhat restricted, as it needs the ability to efficiently project sound (so have a hole through the device's casing), yet not interfere with other aspects of the device (for example traditional speakers cannot be placed on the region of the device housing the screen).

[00057] Modern smartphones may comprise multiple microphones, each placed in a different location of the smartphone. An example is the Apple iPhone 5, which has three microphones, one on the top front-side, one on the bottom, and one on the back. Further, additional external microphones may be connected to the smartphone. Multiple microphones may be used to derive directional information for captured sound, which improves the evaluation of the acoustic performance, in particular deriving the acoustic model.

[00058] While most current smartphones have a ridged body, some devices use a flexible body whereby the shape of the device can be changed. Traditionally, a smartphone may, e.g., have two rigid parts that may be hinged together and thus rotatable around the hinge to be in an open position or closed position. The two rigid parts may alternatively be connected such that they are slideable with respect to each other.

[00059] Another enabler of flexible devices is the use of flexible electronics, where the electronic components are mounted on flexible substrates. Recent developments in the printing of flexible components, such a screens and batteries, have greatly enhanced the future potential of flexible devices. Where flexible devices have the ability to modify their shape using internal components, such as micro-actuators, then the device can shift its shape under its own volition. Micro- actuators may in an example comprise electroactive polymers that that exhibit a change in size or shape when stimulated by an electric field. A micro-actuator may alternatively be made of ceramic piezoelectric materials.

[00060] According to the disclosed method, audible sound is emitted by at least one loudspeaker of the sound emitting device and is more or less simultaneously captured by the microphone arrangement, which may be comprised in the sound emitting device or connected to the sound emitting device. This captured audible sound, or a set of parameters derived from the captured sound, may be compared to a stored preference, and/or the emitted sound, and where the captured sound does not match the preference to within a given tolerance the shape of the device may be changed. Following the change in shape, audio may again be emitted, captured and analysed, and an assessment as to whether further changes in shape would likely be beneficial may be made. Based upon this assessment the shape of the sound emitting device may further be modified.

[00061 ] A variation on this concept is that the sound emitting device first makes an assessment of its surroundings and using this assessment determines the best shape to use.

[00062] As described above, the sound emitting device may emit audible sound by means of at least one loudspeaker and then capture the audible sound after having been affected by the surroundings of the sound emitting device. The sound emitting device may analyse the captured audible sound in order to derive a set of data representing the captured audible sound, e.g., in form of a parametric representation or a set of amplitudes of wavelengths or wavelength ranges of the captured audible sound. The data can be compared to data which is derived correspondingly from the emitted audible sound and/or the one or more

preferences, hereinafter also referred to as Desired Acoustic Performance (DAP).

[00063] The DAP and the captured audible sound may comprise a set of values describing acoustic power at a set of wavelengths or wavelength ranges, preferably using relative values. The DAP and the captured audible sound may further comprise a ratio of level of sound detected in different microphones of the microphone arrangement, and the presence or absence of specific acoustic phenomena such as standing waves.

[00064] The sound emitting device evaluates the acoustic performance of the sound emitting device based on the captured audible sound and the emitted audible sound and/or the DAP in order to determine whether the sound emitting device should change shape or not. If the sound emitting device is to change shape, it may further or possibly also determine which shape to assume based on the evaluation.

[00065] When the sound emitting device determines which shape to assume, the sound emitting device may consult a lookup table to determine the best 'first change' in shape. Such a lookup table may be based on heuristic rules and may use the comparison of DAP and the captured audible sound alone or contextual information derived from sensors in the sound emitting device, e.g., an

understanding of where surfaces close to the loudspeaker(s) are located. The change in shape may be incremental (i.e., a small change is made and the effect of this change estimated by emitting and capturing a further audible sound) or an assessment of the likely 'best' shape is made and the device directly changes to this shape. The estimation of shape change, or selection of which shape to change to, may be enhanced if the sound emitting device has knowledge of the properties of the device itself. For example a sound may be enhanced if the device 'curls up on itself thus using its own surface to modify the sound, and such configurations may be usefully included in the assessment.

[00066] The audible sound may be generated by the sound emitting device and it may be a specific tone, a piece of music, speech, noise, etc. In other words it may be a general sound (e.g., the song the user wishes to hear, or a notification sound) or it may be a specific sound used for this purpose, i.e., one that has specific characteristics to make the evaluation easier, for example white noise with constant power over a given range of wavelengths, or pink noise which carries an equal amount of power in each octave.

[00067] The method may be triggered manually by a user requesting to play out audio. Alternatively, the sound emitting device may either continuously,

periodically, or randomly, capture emitted audible sound during playout to detect if surroundings have changed such that the acoustic performance of the sound emitting device has changed. The surroundings may change due to an item being placed on top of the device or next to the device. The surroundings may also change due to the sound emitting device being moved, e.g., placed in a pocket or on a new surface. The method may alternatively be trigged by a user requesting evaluation of the acoustic performance or by a change in DAP.

[00068] The sound emitting device may further detect any change in

surroundings by means of proximity sensors comprised in the sound emitting device, by means of a camera comprised in the device, or by capturing audible sound and performing the method anew in order to evaluate the acoustic performance based on the captured audible sound and at least one of the emitted audible sound and the DAP.

[00069] Finding or selecting a shape to change to from a current shape may be based on matching between a DAP in a lookup table and the captured audible sound, matching the environmental context in which the sound emitting device is being used, as determined by comparing measurements made by sensors in the sound emitting device to a lookup table, or by manual user input. [00070] As described above, the change of shape based on the evaluation of the captured audible sound could be random (within the bounds of the allowable shapes that the sound emitting device may assume), or some heuristic method could be used to determine the change in shape. Also the change in shape could be determined based on pre-existing knowledge of how the sound emitting device's own surfaces could affect the sound.

[00071 ] An exemplifying method of comparison used for the evaluation could be to compare the power of certain wavelengths or wavelength ranges in the emitted audible sound and to the power of the same wavelengths or wavelength ranges in the captured audible sound, with the DAP containing a description of the allowable change of each of the specified wavelengths or wavelength ranges. Where the power is changing (for example if music is playing) then the waveforms of the emitted and captured audible sound are matched. For a sound with constant power this restriction is lessened, however the capturing of sound has to be 'time- boxed' to ensure it is representative of the emitted audio. In other words, the comparison of emitted audio and captured audio needs to be using the same piece of the audio recording. If it is a constant sound this is easy - emit a block of sound for 10ms and receive the sound and compare etc. But for music, where the sound is varying then some matching may have to take place. Thus, the waveforms of the emitted and received audio have to be temporally matched.

[00072] The allowable shapes may be specific to a context (e.g., device location, device stability, how the device has been placed on a surface etc.), or the application providing the audible sound (e.g., a music playing application may have a greater range of allowable shapes compared to an application using sound as notification).

[00073] Rather than iterating the sound emitting device through a range of shapes and monitoring and comparing the captured audible sound after each shape change, the sound emitting device could make an initial estimation of the surfaces in its surroundings and then algorithmically derive the likely best shape to assume, or adopt. The assessment of the close surfaces may be made via an acoustic method (e.g., ultrasound) or via image capture as the device was placed in its location. The assessment of the local surroundings may be based on an estimation as to whether structures on a given side of the sound emitting device are likely to absorb certain wavelengths of sound, support the creation of an acoustic standing wave, or lead to reverberation, etc.

[00074] The microphone arrangement may include a microphone array capable of beamforming or spatial filtering. Such capability may enhance selection of shape change in order to improve the acoustic performance. Such a microphone arrangement may be used in conjunction with an emitted audible sound to determine the location of surfaces in the sound emitting device's location.

[00075] Figure 2a is an illustration of four different examples of changing the shape of the sound emitting device. In the first example, on the top of the figure, the shape shifting device is shown in a first shape on the left. When the sound emitting device changes shape, a rod may have its position changed from being aligned along the surface of the sound emitting device to instead be protruding from the surface of the sound emitting device. In this manner, the shape of the sound emitting device is changed such that a part of it is lifted from the surface upon which it is laying, thus altering the effect of the surroundings on the emitted audible sound. Alternatively, the rod could be an expandable chamber which may have liquid or air pumped into or out of the expandable chamber in order to lift a part of the sound emitting device in order to alter the effect of the surroundings on the emitted audible sound.

[00076] In the second example, the sound emitting device may comprise flexible electronics enabling the sound emitting device to be curved in order to lift a part of the sound emitting device, thereby altering the effect of the surroundings on the emitted audible sound. Alternatively, the sound emitting device may comprise two parts, or bodies, that are rotatable around a hinging arrangement in order to lift a part of the sound emitting device, thereby altering the effect of the surroundings on the emitted audible sound. [00077] In the third example, the sound emitting device may correspond to the second example, however, the bending or rotating is performed in the "other" direction so at to create a small space underneath the sound emitting device, between the sound emitting device and the surface upon which the sound emitting device is laying.

[00078] In the first three examples, the sound emitting device is illustrated to the rightmost in the figure as a rectangle.

[00079] In the fourth example, at the bottom of figure 2a, the sound emitting device is illustrated comprising three different parts as can be seen in the rightmost in the figure. The three parts may be connected together, e.g., by two hinging arrangements, around which the respective parts may rotate. The sound emitting device may, e.g., comprise an electric motor that may rotate at least two of the three parts around one of the hinging arrangements in order to change the shape of the sound emitting device.

[00080] Figure 2b illustrates yet another example of a sound emitting device having five parts (see the rightmost part of the figure) and being connected, or coupled together, by means of four hinging arrangements. Just as described above, the different parts of the sound emitting device may be moved, or rotated, around a respective hinging arrangement, wherein a plurality of different shapes may be assumed by the sound emitting device.

[00081 ] Embodiments herein also relate to a sound emitting device configured for changing its acoustic performance. The sound emitting device has the same technical features, objects and advantages as the method performed by the sound emitting device described above. The sound emitting device will hence only be described in brief in order to avoid unnecessary repetition.

[00082] Embodiments of such a sound emitting device will now be described with reference to figures 3 and 4. The sound emitting device comprises, or is connectable to, a microphone arrangement and comprises at least one loudspeaker. The sound emitting device is further operable to assume at least two different shapes. Figures 3 and 4 illustrate the sound emitting device being configured for emitting audible sound using the at least one loudspeaker, for capturing the emitted audible sound using the microphone arrangement, and for evaluating the acoustic performance of the sound emitting device based on the captured audible sound and the emitted audible sound. The sound emitting device is further configured for changing the shape of the sound emitting device based on the evaluated acoustic performance.

[00083] The sound emitting device may be realised or implemented in various different ways. A first exemplifying implementation or realisation is illustrated in figure 3. Figure 3 illustrates the sound emitting device 300 comprising a processor 321 and memory 322, the memory comprising instructions, e.g., by means of a computer program 323, which when executed by the processor 321 causes the sound emitting device 300 to emit audible sound using the at least one loudspeaker, to capture the emitted audible sound using the microphone arrangement, and to evaluate the acoustic performance of the sound emitting device based on the captured audible sound and the emitted audible sound. The memory further comprises instructions, which when executed by the

processor 321 causes the sound emitting device to 300 to change the shape of the sound emitting device based on the evaluated acoustic performance.

[00084] Figure 3 also illustrates the sound emitting device to 300 comprising a memory 310. It shall be pointed out that figure 3 is merely an exemplifying illustration and memory 310 may be optional, be a part of the memory 322 or be a further memory of the sound emitting device to 300. The memory may for example comprise information relating to the sound emitting device 300, to statistics of operation of the sound emitting device to 300, to evaluations of the acoustic performance performed for previously assumed shapes, just to give a few examples. Figure 3 further illustrates the sound emitting device to 300 comprising processing means 320, which comprises the memory 322 and the processor 321 . Still further, figure 3 illustrates the sound emitting device to 300 comprising an acoustic unit 330. The acoustic unit 330 comprises at least one loudspeaker and a microphone arrangement, or means for connecting a microphone arrangement to the sound emitting device 300.

[00085] An alternative exemplifying implementation of the sound emitting device is illustrated in figure 4. Figure 4 illustrates the sound emitting device 400 comprising an emitting unit 403 for emitting audible sound using the at least one loudspeaker, and a capturing unit 404 for capturing the emitted audible sound using the microphone arrangement. The sound emitting device 400 further comprises an evaluating unit 405 for evaluating the acoustic performance of the sound emitting device based on the captured audible sound and the emitted audible sound, and a changing unit 406 for changing the shape of the sound emitting device based on the evaluated acoustic performance.

[00086] In figure 4, the sound emitting device 400 is also illustrated

comprising a memory 402 for storing data. Further, the sound emitting device 400 may comprise a control or processing unit (not shown) which in turn is connected to the different units 403-405. It shall be pointed out that this is merely an illustrative example and the sound emitting device 400 may comprise additional or alternative units or modules which execute the functions of the sound emitting device 400 in the same manner as the units illustrated in figure 4.

[00087] It should be noted that the functional units illustrated in figure 4 may be implemented using any suitable combination of software and hardware means/circuits etc. Thus, the embodiments are generally not limited to the shown structures of the sound emitting device 400 and the functional units. Hence, the previously described exemplary embodiments may be realised in many ways. For example, one embodiment includes a computer-readable medium having instructions stored thereon that are executable by the control or processing unit for executing the method steps in the sound emitting device 400. The instructions executable by the computing system and stored on the computer-readable medium perform the method steps of the sound emitting device 400 as set forth in the claims and described hereinbefore. [00088] The sound emitting device has the same possible advantages as the method performed by the sound emitting device described hereinbefore. One possible advantage is that a degradation of the emitted audible sound due to the surroundings of the sound emitting device may be reduced or totally overcome. Another possible advantage is that specific sound characteristics may be achieved by assuming a shape of the device that enables those specific sound

characteristics.

[00089] According to an embodiment of the invention, the microphone

arrangement comprises at least one microphone.

[00090] According to still another embodiment, evaluating the acoustic

performance is based on a respective representation of the emitted audible sound and the captured audible sound.

[00091 ] According to yet another embodiment, the sound emitting device is configured for evaluating the acoustic performance by comparing a representation of the captured audible sound with one or more preferences, and for changing the shape of the sound emitting device if the captured audible sound deviates at least to a predetermined extent from the one or more preferences.

[00092] According to another embodiment, the sound emitting device further is configured for deriving an acoustic model of the surrounding of the sound emitting device based on the captured audible sound and/or the evaluated acoustic performance.

[00093] According to still another embodiment, the sound emitting device is configured for changing the shape based on the acoustic model.

[00094] According to yet another embodiment, the sound emitting device is further configured for emitting further audible sound, capturing the emitted further audible sound, evaluating the further captured emitted audible sound, and for changing the shape based on a comparison of the acoustic performance evaluated for the audible sound and the acoustic performance evaluated for the further emitted audible sound.

[00095] According to another embodiment, the sound emitting device is further configured for changing the shape of the sound emitting device by evaluating a plurality of shapes of the sound emitting device, determining which of the evaluated shapes best matches one or more preferences, and changing to that shape.

[00096] According to a further embodiment, the shape of the sound emitting device is changed by means of at least one actuator.

[00097] According to still another embodiment, the sound emitting device is configured for changing the shape of the sound emitting device by means of a motor.

[00098] According to yet another embodiment, the sound emitting device comprises at least two parts having different thermal expansion coefficients. The sound emitting device is configured for changing its shape by changing a temperature of at least a portion of the sound emitting device, wherein the at least two parts expand differently, thereby changing the shape of the sound emitting device.

[00099] According to another embodiment, the sound emitting device is configured for changing the shape of the sound emitting device by at least one of

(i) pumping air into, or letting air out of, an expandable chamber of the device, and

(ii) pumping liquid into, or letting liquid out of, the expandable chamber.

[000100] Figure 5 schematically shows an embodiment of an arrangement 500 in a sound emitting device 400. Comprised in the arrangement 500 in the sound emitting device 400 are a processing unit 506, e.g., a Digital Signal Processor, DSP. The processing unit 506 may be a single unit or a plurality of units to perform different actions of procedures described herein. The arrangement 500 of the sound emitting device 400 may also comprise an input unit 502 for receiving audible sound, and an output unit 504 for emitting audible sound. The input unit and the output unit may be arranged as an integrated entity or as illustrated in the example of figure 4, as one or more interfaces 401 .

[000101 ] Furthermore, the arrangement 500 in the sound emitting device 400 comprises at least one computer program product 508 in the form of a memory, e.g., a Read-Only Memory (ROM), a Random Access memory (RAM), a Flash memory, or a hard drive. The computer program product 508 comprises a computer program 510, which comprises instructions, which when executed in the processing unit 506 in the arrangement 500 in the sound emitting device 400 causes the sound emitting device to perform the methods described herein.

[000102] The computer program 510 may be configured as a computer program code structured in computer program modules 510a-510e. Hence, in an

exemplifying embodiment, the instructions in the computer program of the arrangement 500 in the sound emitting device 400 comprises an emitting module for emitting audible sound using the at least one loudspeaker. The computer program further comprises a capturing module for capturing the emitted audible sound using the microphone arrangement. Still further, the computer program further comprises an evaluating module for evaluating the acoustic performance of the sound emitting device based on the captured audible sound and the emitted audible sound; and a changing unit, or module, for causing the sound emitting device to change its shape based on the evaluated acoustic performance.

[000103] Although the embodiments disclosed above in conjunction with figure 4 are implemented as computer program modules, which when executed in the respective processing unit causes the sound emitting device to perform the actions described above in the conjunction with figures mentioned above, alternative embodiments may at least partly be implemented as hardware circuits.

[000104] The processor may be a single Central Processing Unit (CPU) but could also comprise two or more processing units. For example, the processor may include general purpose microprocessors, instruction set processors and/or related chips sets, and/or special purpose microprocessors such as Application Specific Integrated Circuits (ASICs). The computer program may be carried by a computer program product connected to the processor, such as a computer readable medium on which the computer program is stored. For example, the computer program product may be a Flash memory, a Random-Access Memory (RAM), a Read-Only Memory (ROM), or a hard drive. The computer program modules described above could in alternative embodiments be distributed on different computer program products in the form of memories within the sound emitting device.

[000105] It is to be understood that the choice of interacting units, as well as the naming of the units within this disclosure are only for exemplifying purpose, and nodes suitable to execute any of the methods described above may be configured in a plurality of alternative ways in order to be able to execute the suggested procedure actions.

[000106] It should also be noted that the modules and units described in this disclosure are to be regarded as functional entities and not necessarily as separate physical entities.

[000107] While the invention has been described in terms of several embodiments, it is contemplated that alternatives, modifications, permutations, and equivalents thereof will become apparent upon reading of the specifications and study of the drawings.

Claims

1 . A method (100) performed by a sound emitting device for changing its acoustic performance, the sound emitting device comprising, or being connectable to, a microphone arrangement and comprising at least one loudspeaker, the sound emitting device being operable to assume at least two different shapes, the method comprising:

- emitting (1 10) audible sound using the at least one loudspeaker,

- capturing (120) the emitted audible sound using the microphone

arrangement,

- evaluating (130) the acoustic performance of the sound emitting device based on the captured audible sound and the emitted audible sound, and

- changing (140) the shape of the sound emitting device based on the

evaluated acoustic performance.

2. The method (100) according to claim 1 , wherein the microphone arrangement comprises at least one microphone.

3. The method (100) according to claim 1 or 2, wherein evaluating (130) the acoustic performance is based on a respective representation of the emitted audible sound and the captured audible sound.

4. The method (100) according to any of claims 1 -3, wherein

evaluating (130) the acoustic performance comprises comparing a representation of the captured audible sound with one or more preferences, and changing (140) the shape of the sound emitting device if the captured audible sound deviates at least to a predetermined extent from the one or more preferences.

5. The method (100) according to claims 1 -4, further comprising deriving an acoustic model representing the surrounding of the sound emitting device based on the captured audible sound and/or the evaluated acoustic performance.

6. The method according to claim 5, wherein the shape of the sound emitting device is changed based on the acoustic model.

7. The method (100) according to claims 1 -4, further comprising emitting further audible sound, capturing the emitted further audible sound, evaluating the further captured emitted audible sound, and changing the shape based on a comparison of the acoustic performance evaluated for the audible sound and the acoustic performance evaluated for the further emitted audible sound.

8. The method (100) according to any of claims 1 -4, wherein

changing (140) the shape of the sound emitting device further comprises, when a plurality of shapes have been evaluated by the sound emitting device: determining which of the evaluated shapes best matches one or more preferences, and changing to that shape.

9. The method (100) according to any of claims 1 -8, wherein the shape of the sound emitting device is changed by means of at least one actuator.

10. The method (100) according to any of claims 1 -8, wherein the shape of the sound emitting device is changed by means of a motor.

1 1 . The method (100) according to any of claims 1 -8, wherein the sound emitting device comprises at least two parts having different thermal expansion coefficients, such that the at least two parts expand differently if their temperature is changed, wherein the shape of the sound emitting device is changed by heating or cooling at least a portion of the sound emitting device.

12. The method (100) according to any of claims 1 -8, wherein

changing (140) the shape of the sound emitting device comprises at least one of

(ii) pumping liquid into, or letting liquid out of, the expandable chamber.

13. A sound emitting device (300, 400) configured for changing its acoustic performance, the sound emitting device comprising, or being connectable to, a microphone arrangement and comprising at least one loudspeaker, the sound emitting device being operable to assume at least two different shapes, the sound emitting device being configured for:

- emitting audible sound using the at least one loudspeaker,

- capturing the emitted audible sound using the microphone arrangement,

- evaluating the acoustic performance of the sound emitting device based on the captured audible sound and the emitted audible sound, and

- changing its shape based on the evaluated acoustic performance.

14. The sound emitting device (300, 400) according to claim 13, wherein the microphone arrangement comprises at least one microphone.

15. The sound emitting device (300, 400) according to claim 13 or 14, wherein evaluating the acoustic performance is based on a respective

representation of the emitted audible sound and the captured audible sound.

16. The sound emitting device (300, 400) according to any one of claims 13- 15, wherein the sound emitting device is configured for evaluating the acoustic performance by comparing a representation of the captured audible sound with one or more preferences, and for changing its shape if the captured audible sound deviates at least to a predetermined extent from the one or more preferences.

17. The sound emitting device according to claims 13-16, being further configured for deriving an acoustic model representing the surrounding of the sound emitting device based on the captured audible sound and/or the evaluated acoustic performance.

18. The sound emitting device (300, 400) according to claim 17, wherein the sound emitting device is configured for changing its shape based on the acoustic model.

19. The sound emitting device (300, 400) according to claims 13-16, being further configured for emitting further audible sound, capturing the emitted further audible sound, evaluating the further captured emitted audible sound, and for changing its shape based on a comparison of the acoustic performance evaluated for the audible sound and the acoustic performance evaluated for the further emitted audible sound.

20. The sound emitting device (300, 400) according to any of claims 13-16, wherein the sound emitting device is further configured for changing its shape by evaluating a plurality of shapes of the sound emitting device, determining which of the evaluated shapes best matches one or more preferences, and changing to that shape.

21 . The sound emitting device (300, 400) according to any of claims 13-20, wherein the sound emitting device is configured for changing its shape by means of at least one actuator.

22. The sound emitting device (300, 400) according to any of claims 13-20, wherein the sound emitting device is configured for changing its shape by means of a motor.

23. The sound emitting device (300, 400) according to any of claims 13-20, wherein the sound emitting device comprises at least two parts having different thermal expansion coefficients, such that of the at least two parts expand differently is their temperature is changed, wherein the shape of the sound emitting device is changed by heating or cooling the sound emitting device.

24. The sound emitting device (300, 400) according to any of claims 13-20, wherein the sound emitting device is configured for changing its shape by at least one of (i) pumping air into, or letting air out of, an expandable chamber of the device, and (ii) pumping liquid into, or letting liquid out of, the expandable chamber.

25. A Computer program (510), comprising computer readable instructions, which when run in a processing unit (506) comprised in a sound emitting

device (400) causes the sound emitting device (400) to perform the method according to any of claims 1 -12.

26. A Computer program product (508) comprising the computer program (510) according to claim 25.