Wireless sound transmission and method

Patent metadata

Field	Value
Publication number	US-9832575-B2
Application number	US-201214373140-A
Country	US
Kind code	B2
Filing date	Jan 20, 2012
Priority date	Jan 20, 2012
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

A system for providing sound to at least one user has at least one audio signal source, a transmission unit with a digital transmitter audio data packets from the audio signal source via a wireless digital audio link; at least one receiver unit having at least one digital receiver; and a hearing stimulator responsive to audio signals from the receiver unit. The transmission unit encodes the audio signal as audio data blocks distributed onto at least two audio data packets, one of which is a low-quality packet, and one of which is a high quality packet only a low-quality version of the audio signal being retrievable from the low-quality packets, and a high-quality version of the audio signal being retrievable from both the low-quality packets and the high-quality packets. The low-quality packets and the high-quality packets are transmitted in respective dedicated slots of a multiple access protocol frame.

First claim

The invention claimed is:

1. A system for providing audio signals, comprising:
an audio signal source to provide an audio signal;
a transmission unit comprising a digital transmitter for applying a digital modulation scheme to transmit the audio signal as audio data packets from the audio signal source via a wireless digital audio link,
wherein the transmission unit is configured to encode the audio signal in such a manner that each audio data block is distributed onto at least two audio data packets in such a manner that one of the at least two audio data packets is a low-quality packet including an encoded low-quality portion of the audio signal, and one of the at least two audio data packets is a high quality packet that includes an encoded high-quality portion of the audio signal with regard to the low quality portion, so that by decoding of the low-quality audio packet only a low-quality portion of the audio signal is retrievable, whereas by decoding of both the low-quality and the high-quality audio data packets a high-quality portion of the audio signal is retrievable, and
wherein the transmission unit is configured to transmit the low-quality audio data packet in a dedicated slot of a multiple access protocol frame and configured to transmit the high-quality audio data packet in another dedicated slot of the multiple access protocol frame; and

a receiver unit for reception of a modulated audio signal from the transmission unit via the wireless digital audio link,
wherein the receiver unit is configured to receive and decode the low-quality audio data packet while sleeping during the slot dedicated to the transmission of the high-quality audio data packet.

2. The system of claim 1 , wherein the transmission unit is configured to split the audio signal into two spectral sub-bands prior to encoding,
wherein each sub-band is encoded by a separate encoder.

3. The system of claim 1 , wherein the low-quality audio data packet includes only a lowest sub-band associated with the audio signal.

4. The system of claim 1 , wherein the low-quality audio data packet includes only the most significant bits of a sub-band, with the remaining bits are included in the high-quality audio data packet.

5. The system of claim 1 , wherein the transmission unit includes a two-stage encoder, wherein the two-stage encoder is configured to encode the low-quality audio data packet, wherein the two-stage encoder includes a first stage for generating the most significant bits included in the low-quality audio data packet, a unit for computing a residual quantization error of the first stage, and a second stage for encoding a computed residual quantization error of the first stage to generate remaining bits included in the high-quality audio data packet.

6. The system of claim 1 , wherein the transmission unit includes a two-stage encoder, wherein the two-stage encoder is configured to encode the audio signal, wherein the two-stage encoder includes a first stage for generating said most significant bits included in the low-quality audio data packet, a unit for computing a residual quantization error of the first stage, and a second stage for encoding a computed residual quantization error of the first stage to generate remaining bits included in the high-quality audio data packet, and wherein the most significant bits are retrieved by decoding of the low-quality audio data and adding them to the least significant bits of retrieved by decoding of the high-quality audio data packet.

7. The system of claim 1 , wherein the low-quality audio data includes only 2 sub-bands, wherein the high-quality audio data packet includes at least one additional sub-band compared to the low-quality audio data packet.

8. The system of claim 1 , wherein the audio signal retrieved by decoding both the low-quality audio data packet and the high-quality audio data packet has an increased bandwidth and an increased quantization resolution compared to the audio signal retrieved by decoding only the low-quality audio data packet.

9. The system of claim 1 , wherein the audio signal retrieved by decoding both the low-quality and the high-quality audio data packets has a higher quantization resolution in lower frequency sub-bands compared to higher frequency sub-bands.

10. The system of claim 1 , wherein an Adaptive Differential Pulse-Code Modulation (ADPCM) codec is used.

11. The system of claim 10 , wherein the low-quality audio data packet is transmitted at least twice in subsequent slots, in the same frame, without expecting acknowledgement messages from the receiver unit, and wherein the frames are structured for unidirectional broadcast transmission of the audio data packets.

12. The system of claim 1 , wherein the low-quality and high-quality audio data packets are transmitted at a different frequency according to a frequency hopping sequence.

13. The system of claim 1 , wherein the audio signal source is a microphone arrangement integrated into or connected to the transmission unit for capturing a speaker's voice.

14. The system of claim 1 , wherein the transmission unit comprises an audio signal processing unit for processing the audio signals captured by the microphone arrangement prior to being transmitted.

15. The system of claim 1 , wherein the transmission unit is configured to establish a wireless digital audio link at a carrier frequency in a 2.4 GHz industrial, scientific, and medical (ISM) radio band.

16. The system of claim 1 , wherein the transmission unit configured to be coupled to an external audio device.

17. The system of claim 1 , wherein the receiver unit is physically coupled to or integrated into an ear-worn device.

18. The system of claim 1 , wherein the receiver unit is integrated within an audience loudspeaker.

19. The system of claim 1 , wherein the multiple access protocol frame is a Time-Division multiple access (TDMA) frame.

20. A method for providing sound, the method comprising:
providing an audio signal from an audio signal source to a transmission unit comprising a digital transmitter for applying a digital modulation scheme;
encoding the audio signal,
wherein encoding includes encoding such that each audio data block is distributed onto at least two audio data packets in such a manner that one of the audio data packets is a low-quality audio data packet including an encoded low-quality portion of the audio signal, and one of the audio data packets is a high quality audio data packet including a high-quality portion of the audio signal with regard to a low-quality portion, so that by decoding of the low-quality audio data packet only the low-quality portion of the audio signal is retrieved, whereas by decoding of both the low-quality and the high-quality audio data packets a high-quality portion of the audio signal is retrieved;

transmitting the encoded audio signal via a digital wireless audio link from the transmission unit to a receiver unit,
wherein the low-quality audio data packet is transmitted in a dedicated slot of a multiple access protocol frame and the high-quality audio packet is transmitted in another dedicated slot of the multiple access protocol frame, and
wherein the receiver unit is configured to decode the low-quality audio data packet only while sleeping during the another slot dedicated to the transmission of the high-quality audio data packet;
decoding the transmitted audio signal; and
providing the decoded audio signal to a user.

21. The method of claim 20 , wherein the low-quality

Assignees

• Secall Marc
• Jost Timothée
• El-Hoiydi Amre
• Sonova Ag

Inventors

• Secall Marc
• Jost Timothée
• El-Hoiydi Amre

Classifications

• H04B1/713

  using frequency hopping · CPC title

• G10L19/04

  using predictive techniques · CPC title

• H04B2201/71361

  Slow frequency hopping · CPC title

• G10L19/008

  Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing · CPC title

• H04R25/554 Primary

  using a wireless connection, e.g. between microphone and amplifier or using Tcoils · CPC title