Method and device for spectral expansion of an audio signal

Patent metadata

Field	Value
Publication number	US-2023142711-A1
Application number	US-202318096655-A
Country	US
Kind code	A1
Filing date	Jan 13, 2023
Priority date	Jan 15, 2013
Publication date	May 11, 2023
Grant date	—

Abstract

A method and device for automatically increasing the spectral bandwidth of an audio signal including generating a “mapping” (or “prediction”) matrix based on the analysis of a reference wideband signal and a reference narrowband signal, the mapping matrix being a transformation matrix to predict high frequency energy from a low frequency energy envelope, generating an energy envelope analysis of an input narrowband audio signal, generating a resynthesized noise signal by processing a random noise signal with the mapping matrix and the envelope analysis, high-pass filtering the resynthesized noise signal, and summing the high-pass filtered resynthesized noise signal with the input narrowband audio signal. Other embodiments are disclosed.

First claim

We claim:

1 . A method comprising:
receiving a command to initiate communication in a noisy environment; retrieving a wideband reference signal and narrowband reference signal from memory, wherein the narrowband reference signal was generated from an ear canal microphone in an earpiece, and the wideband reference signal was generated from an ambient sound microphone in the same earpiece; receiving an ear canal signal; generating a modified ear canal signal by spectrally expanding the ear canal signal using the wideband reference signal and the narrowband reference signal; and sending the modified ear canal signal to a communication device.

2 . The method according to claim 1 , further comprising:
receiving an ambient sound signal; generating a background noise signal from the ambient sound signal; generating the command to initiate communication when a pressure level of the background noise signal is above a value.

3 . The method according to claim 2 , wherein the pressure level is an averaged pressure level across frequencies from 50 Hz to 10 kHz.

4 . The method according to claim 2 , wherein the wideband reference signal was generated when the pressure level is below the value.

5 . The method according to claim 4 , wherein the narrowband reference signal was generated when the pressure level is below the value.

6 . The method according to claim 1 , wherein spectrally expanding the ear canal signal is performed by applying a mapping matrix, wherein the mapping matrix is generated using the wideband reference signal and the narrowband reference signal.

7 . The method according to claim 6 , wherein the mapping matrix is a transformation matrix to predict high frequency energy from a low frequency energy envelope.

8 . The method according to claim 7 further comprising:
generating the low frequency energy envelope from the ear canal signal prior to generating a modified ear canal signal.

9 . The method according to claim 1 , wherein the ear canal signal was received from a remote communication device.

10 . A method comprising:
receiving a command to initiate communication in a noisy environment; receiving a wideband reference signal and narrowband reference signal, wherein the narrowband reference signal was generated from an ear canal microphone in an earpiece of a remote communication system, and the wideband reference signal was generated from an ambient sound microphone in the same earpiece; receiving an ear canal signal from the remote communication system; generating a modified ear canal signal by spectrally expanding the ear canal signal using the wideband reference signal and the narrowband reference signal; and sending the modified ear canal signal to a speaker of a communication system worn by a user.

11 . The method according to claim 10 , further comprising:
receiving an ambient sound signal from an ambient sound microphone in an earpiece worn by the user; generating a background noise signal from the ambient sound signal; generating the command to initiate communication when a pressure level of the background noise signal is above a value.

12 . The method according to claim 11 , wherein the pressure level is an averaged pressure level across frequencies from 50 Hz to 10 kHz.

13 . The method according to claim 10 , wherein spectrally expanding the ear canal signal is performed by applying a mapping matrix, wherein the mapping matrix is generated using the wideband reference signal and the narrowband reference signal.

14 . The method according to claim 13 , wherein the mapping matrix is a transformation matrix to predict high frequency energy from a low frequency energy envelope.

15 . The method according to claim 14 further comprising:
generating the low frequency energy envelope from the ear canal signal prior to generating a modified ear canal signal.

16 . The method according to claim 1 , wherein the command is initiated from a user interface.

17 . The method according to claim 10 , wherein the command is initiated from a user interface.

Assignees

• Staton Techiya Llc

Inventors

• Usher John
• Ellis Dan

Classifications

• G10L21/0388 Primary

  Details of processing therefor · CPC title

• H04R1/028

  associated with devices performing functions other than acoustics, e.g. electric candles · CPC title

• H04R5/033

  Headphones for stereophonic communication {(details thereof, e.g. relating to batteries, cables or control elements H04R1/10)} · CPC title

• H04R2420/07

  Applications of wireless loudspeakers or wireless microphones · CPC title

• H04R1/1083

  Reduction of ambient noise (active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06) · CPC title