WO2010133991A1

WO2010133991A1 - Method for operating an acoustic system and wearable acoustic device

Info

Publication number: WO2010133991A1
Application number: PCT/IB2010/051970
Authority: WO
Inventors: Heribert Baldus; Antonios Argyriou; Karin Klabunde; Thomas Falck; Vincentius Buil; Lucas Geurts; Tim Schenk; Sotir Ouzounov
Original assignee: Koninklijke Philips Electronics NV
Current assignee: Koninklijke Philips NV
Priority date: 2009-05-19
Filing date: 2010-05-05
Publication date: 2010-11-25
Anticipated expiration: 2011-11-19

Abstract

The present invention relates to a method for operating an acoustic system comprising an audio source, and at least one wearable acoustic device, the method comprising: the audio source transmitting an audio signal to a master device, via a short range wireless communication protocol, and the master device transmitting all or part of the audio signal to the wearable acoustic device, regarded as a slave device, via body-coupled communication. The present invention also relates to a method for automatically switching on or off a mobile device carrying out body-coupled communication. The present invention also relates to a wearable acoustic device.

Description

METHOD FOR OPERATING AN ACOUSTIC SYSTEM AND WEARABLE ACOUSTIC DEVICE

FIELD OF THE INVENTION The present invention relates to the use of body-coupled communications for operating an acoustic system.

This invention is, for example, relevant for acoustic system comprising earpieces or headphones.

BACKGROUND OF THE INVENTION

Conventional headphones or earpieces are generally wired to audio devices, like mp3 player. However, such systems are not really convenient to use for the following reasons: wires disturb the user because he cannot move as freely as usual, wires do not allow to share music with another person, - moreover, there is a risk of breaking one of the wires, with the complete headset being unusable anymore.

Thus, it has been proposed short range wireless solutions, for example using radio- frequency (RF) or Bluetooth.

Wireless headset solutions based on RF have the following drawbacks: - Limited operating time due to relatively high power consumption of RF transceiver

- Need for manually pairing of headset with mobile device

- Human being is exposed to potentially harmful RF radiation

- Interference with other RF systems operating in the same frequency band - No automatic power on/off and pausing/resuming of music through on/off- body detection

Body coupled communications (BCC) or body-based communication, or near-body communication, has been proposed as a promising alternative to radio frequency (RF) communication as a basis for body area networks. BCC allows exchange of information between a plurality of devices which are at or in close proximity of a human or animal body. This can be achieved by capacitive or galvanic coupling of low-energy electrical fields onto the body surface. Signals are conveyed over the body instead of through the air. As such, the communication is confined to an area close to the body in contrast to RF communications, where a much larger area is covered. Therefore, communication is possible between devices situated on, connected to, or placed close to the body. Moreover, since lower frequencies can be applied than typically applied in RF-based low range communications, it opens the door to low-cost and low-power implementations of body area networks (BANs) or personal area networks (PANs). Hence, the human body is exploited as a communication channel, so that communication can take place with much lower power consumption than in standard radio systems commonly used for BANs (e.g. ZigBee or Bluetooth systems). Since BCC is usually applied in close proximity to the body, it can be used to realize new and intuitive body-device interfaces based on contact or proximity.

SUMMARY OF THE INVENTION It is an object of the invention to propose a method for operating an acoustic system comprising wearable acoustic devices that overcome at least some of the above-mentioned drawbacks.

It is another object of the invention to propose a method allowing use of low-power earpieces or headphones. Yet another object of the invention it to propose earpieces, or headphones, that can be used in combination with existing handheld audio devices such as mobile phones, smart phones, mp3 players.

Another aspect of the invention relates to a wearable acoustic device that may be operated by a method according to the invention. Yet another aspect of the invention relates to a method for automatically switching on and off mobile devices, for example wearable acoustic devices, using body-coupled communication. This aspect will be herein described in combination with the other aspects of the invention, but it can be used independently.

A method for operating an acoustic system comprising an audio device, and at least one wearable acoustic device, the method comprising: the audio device exchanging an audio signal with a master device, via a short range wireless communication protocol, and the master device exchanging all or part of the audio signal with the wearable acoustic device, regarded as a slave device, via body-coupled communication. The audio device is, in some examples, an audio source like a mobile phone, a smart phone, an mp3 player or any other electronic device able to transmit audio signals. In other examples, the audio device is a storage device. Then the wearable acoustic device is, for example, an ear piece, a headphone, a headset, a microphone or any other electronic device that can broadcast sound and be worn by a user.

The short range wireless communication protocol is, advantageously, Bluetooth, but it can be any other protocol, including body-coupled communication.

The invention presents many advantages as follows: body-coupled communication is a technology requiring low-power, thus it allows using small devices with a reduced battery size, body-coupled communication makes it possible to perform audio streaming towards several devices, transmission from the audio source is performed via Bluetooth or another conventional communication protocol, thus this method can be carried out with conventional handheld device without any modification.

The invention also relates to a wearable acoustic device comprising: - means for transmitting or receiving exchanging an audio signal to or from another device, via a short range wireless transmission protocol, means for transmitting or receiving, via body-coupled communication, all or part of the audio signal to or from a distinct wearable acoustic device.

As mentioned before, another aspect of the invention relates to a method for automatically switching on and off mobile devices, using body-coupled communication.

Actually, the invention aims at allowing use of low power devices. Accordingly, these devices need to be switched off or put in standby mode when unused, in order to save energy and battery power.

Conventional devices comprise on/off buttons that have to be mechanically actuated by a user. However, such buttons are not convenient in case of small devices like ear phone.

It is also known to use movement sensors that activate device when being used. However, this solution presents several drawbacks as mentioned below: movement sensor works only for mobile devices that the user carriers and not for stationary devices, - wrong detection may be performed, for example in case of a user resting, stationary, with earphones.

Thus, the invention provides, in one aspect, a method for switching on and off a device, comprising the following steps: determining whether a user is intending to use it or not, and based on this determination, automatically switching on or off.

This aspect of the invention is herein claimed in combination with other aspects, but it can be used independently for any device carrying out body-coupled communication, in any functionality. Indeed, this aspect can be used with any system comprising a receiver and/or a transmitter compatible with body-coupled communication protocol. In the following specification, such a system will be designated as an Active Digital Aura system, or ADA.

The determination of whether a user is intending to use the device or not is made by the device performing a regular polling, comprising one or several of the following steps: detecting interference: a receiver of ADA system is used to regularly measure environment interference; interference pattern changes when the device is touched by a user; this change is different to an interference change that we measure when the system is put somewhere in the environment, measuring signal reflection caused by human body: The body-coupled transmitter sends signal probe; receiver running at the same time; the received signal is 'correlated' with the transmitted signal; the resulting signal (with some filtering) indicates the reflection: this is specific for the human body. This feature is advantageously used with a high bandwidth transceiver. measuring influence of body movement: As in the preceding features, probes are used, but now it is looked at variation in signal strength as function of time. Body movements create fading in this signal, which can specifically be attributed to movement of a person, capacitively sensing of heartbeat signal, or other suited bio signal, of the body: An ADA tag is used to detect on body bio signals. It only receives, and when there is correlation with patterns of a typical bio signal, it concludes / detects that it is located on the body.

These and other aspects of the invention will be apparent from and will be elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described in more detail, by way of example, with reference to the accompanying drawings, wherein: - Figs. 1 to 4 represent different embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to an acoustic system comprising at least some of the following elements: an audio source, for example included in a handheld device, one or many wearable acoustic device(s) such as earpiece, earphone, or headphone, a dongle, acting as master device in some embodiments, used for transmitting signals from the audio source to the acoustic device. The wearable acoustic devices and the dongle must be in contact with the user's body, in order to enable body-coupled communication. However, as regards the audio source, such a contact is not required, for example in case where the short range wireless communication protocol used for transmitting audio signals is Bluetooth.

In a first embodiment, shown on figure 1, a handheld audio device 10 streams a mono or stereo (music) audio signals to an earpiece 11 via Bluetooth (BT). In this first embodiment, the first transmission is performed via Bluetooth. However, this transmission may be performed by any other short-distance wireless communication technology. In a particular example, this first transmission can be performed using different protocols, as follows : the first transmission is performed via body-coupled communication if body contact is available both at the audio source and at the earpiece, and via bluetooth is not contact is available at one side.

Usually, mono signals represent voice signals, and stereo signals represent music. A stereo signal comprises two audio channels, a right one and a left one, who are ideally transmitted respectively with louders situated on the right and the left of a user. Earpiece 11 receiving this Bluetooth signal, considered as the master earpiece in the present embodiment, then transmits a signal to the slave earpiece 12 via body-coupled or near-body communication, also called Active Digital Aurea (ADA). The signal transmitted from the master earpiece to the salve earpiece depends on the initial signal received from the handheld device : - in case the handheld device transmits a mono signal, then this signal is entirely transmitted to the slave earpiece 12, in case the handheld device tranmists a stereo signal, then only data corresponding to one of the audio channels is transmitted to the slave earpiece.

The master earpiece 11 comprises means for discovering the salve earpiece 12 via near-body communication. In case no earpiece is discovered, then the master earpiece does not transmit any signal, in order to save battery power.

Different methods can be carried out by the discovering means: measuring the reflection of tone from ear, since the biometrics of ears are different, or measuring changes of capacity, in transmission and reception of signals. An extension of this first embodiment is shown on figure 2. In this embodiment, the master earpiece 11 not only transmits audio signals to one slave earpiece 12, but also to another slave earpiece 13. This slave earpiece 13 itself comprises means for transmitting audio signal to a slave earpiece 14. In an example, if the audio signal initially transmitted from the handheld device 10 is a stereo signal, then: the master earpiece transmits content of one audio channel to the slave earpiece 12, the master earpiece transmits the complete audio signals to the slave earpiece 13, the salve earpiece 13 transmits one audio channel to the slave earpiece 14.

In this example, earpieces 11 and 12 represent a first pair worn by a first user, and earpieces 13 and 14 represent a second pair worn by a second user. Accordingly, this embodiment makes it possible to share audio stream between several users, i.e. between a first user wearing the audio source and a second user without any audio source. The only requirement for correct operation of this embodiment is that a physical contact exists between the first and second user to allow propagation of the audio signals from earpiece 11 to earpiece 13.

In a second embodiment, shown on figure 3, the master device is not an earpiece but a separate dongle 23 or clip. Thus, in this embodiment, the handheld device 20 transmits, via Bluetooth (BT), an audio signal to the dongle 23. This dongle or clip, generally worn on the body of a user, transmits audio signals to slave earpieces 21 and 22. In an example, wherein the signal transmitted by the handheld device is a mono signal, the dongle 23 transmits entirely this audio signal to both slave earpieces 21 and 22, who then receive the same signal. In another example, wherein the signal transmitted by the handheld device is a stereo signal, thus comprising, the dongle 23 transmits data corresponding to the right channel to slave earpiece 21, situated in the right ear of the user, and transmits data corresponding to the left channel to slave earpiece 22, situated in the left ear of the user.

Accordingly, in this embodiment the slave earpieces 21 and 22 comprise means for determining in which ear they are situated, for example by comparison with the position of the dongle, and for indicating it to the dongle. The dongle 23 comprises means for discovering the slave earpieces 21 and 22 via near-body communication. In case no earpiece is discovered, then the dongle does not transmit any signal, in order to save battery power. In case only one earpiece is detected, then the dongle transmits a signal only to this earpiece. In a particular example, wherein slave earpiece 21 comprises a touch sensor for determining whether the user holds the earpiece in the hand, audio streaming from the dongle 23 to the slave earpiece 21 is started only when the following process has been completed, step by step, by the earpiece: - step 1 : the touch sensor area is touched and the earpiece is not in the ear, which means that the user holds the earpiece, and the dongle is not detected yet by earpiece, step 2: the touch sensor area is touched and the earpiece is in the ear, which means that the user has just placed the earpiece, and the dongle is detected by earpiece) step 3: touch sensor area is released and earpiece is in the ear, and the dongle is still detected by earpiece.

Moreover, as said before, the process is such that the audio stream is automatically paused as soon as the dongle does not detect earpiece anymore.

Such a process also ensures that the audio stream is not started when the earpieces are just held in the hand, which helps saving energy. The third embodiment, shown on Figure 4, is a variant of the second embodiment. In this third embodiment, the master device is a separate adapter 33 receiving the audio signal via a connector from the handheld device. This adapter, for example implemented in a pouch, is being worn on the body and transmits the audio signal as in the second embodiment.

In the present specification and claims the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. Further, the word "comprising" does not exclude the presence of other elements or steps than those listed.

The inclusion of reference signs in parentheses in the claims is intended to aid understanding and is not intended to be limiting.

From reading the present disclosure, other modifications will be apparent to persons skilled in the art. Such modifications may involve other features which are already known in the art of wireless communications and which may be used instead of or in addition to features already described herein.

Claims

1. A method for operating an acoustic system comprising an audio device, and at least one wearable acoustic device, the method comprising: - the audio device exchanging an audio signal with a master device, via a short range wireless communication protocol, and the master device exchanging all or part of the audio signal with the wearable acoustic device, regarded as a slave device, via body-coupled communication.

2. A method as recited in claim 1, wherein the audio device is an audio source or an audio storage system.

3. A method as recited in claim 1 or 2, wherein the transmission is performed using a streaming protocol.

4. A method as recited in claim 1 comprising the step for the master device, before exchanging signals, of detecting the presence of a wearable acoustic device distinct from the master device before performing the transmission.

5. A method as recited in claim 2, wherein the detection is performed by the wearable acoustic device measuring reflection of tone from ear, or by measuring change of capacity of transmitted signals.

6. A method as recited in claim 1 wherein the audio device is an audio source and the master device is a wearable acoustic device, and wherein, in case the audio signal transmitted by the audio source device is a stereo signal, the transmitting step comprises transmitting only one audio channel of the signal to wearable acoustic device.

7. A method as recited in claim 1, wherein the master device is not a wearable acoustic device, comprising the step of determining the position of at least one wearable acoustic device, wherein determining the position consists in determining whether the device is situated in the right or left ear.

8. A method as recited in claim 1, comprising the steps, for the wearable acoustic device, of determining whether a user is intended to use it or not, and based on this determination, automatically switching on or off.

9. A method as recited in claim 7, wherein the determination step comprises performing a regular polling to detect if the device is touched by a user.

10. A method as recited in claim 8, wherein the step of performing the polling comprises at least one of the following : detecting interference, to compare current value with previous and further ones, measuring signal reflection caused by human body, measuring influence of body movement.

11. A wearable acoustic device comprising: means for transmitting or receiving exchanging an audio signal to or from another device, via a short range wireless transmission protocol, means for transmitting or receiving, via body-coupled communication, all or part of the audio signal to or from a distinct wearable acoustic device.

12. A wearable acoustic device as recited in claim 10, comprising: means for determining the nature of the audio signal, i.e. mono or stereo, and wherein the transmitting means comprise means for transmitting, in case of a stereo signal, only one audio channel of the stereo signal, and means for transmitting, in case of a mono signal, the complete signal.