Apparatus And A Method For Audio Signal Processing

Abstract

An apparatus, such as a headset, configured to process audio signals from multiple microphones, comprising: a first pair of microphones (101, 102) outputting a first pair of microphone signals and a second pair of microphones (103, 104) outputting a second pair of microphone signals; a first beamformer (105) and a second beamformer (106) each configured to receive a pair of microphone signals and adapt the spatial sensitivity of a respective pair of microphones as measured in a respective beamformed signal (XL; XR) output from a respective beamformer (105; 106); wherein the spatial sensitivity is adapted to suppress noise relative to a desired signal; a third beamformer (107) configured to dynamically combine the signals (XL; XR) output from the first beamformer (105) and the second beamformer (106) into a combined signal (XC); wherein the signals are combined such that signal energy in the combined signal is minimized while a desired signal is preserved; and a noise reduction unit (109) configured to process the combined signal (XC) from the third beamformer (107) and output the combined signal such that noise is reduced.

Description

[0001]It has been discovered that use of multiple microphones and the use of beamforming techniques provide audio signal reproduction that is superior to single microphone or non-beamforming systems. The multiple microphones are located at different positions and allows so-called spatial sampling which in turn enables cancelling of noise interfering with a desired signal such as a person's voice; this is also known as beamforming, spatial filtering or noise-cancelling. Subsequent time varying post-filters are often applied as a means to further discriminate the person's voice from (background) noise signals.[0002]Multiple microphones and the use of beamforming techniques are frequently embodied in headsets, hearing aids, laptop computers and other electronic consumer devices.[0003]The technical field of beamformers has been extensively researched; however their qualities and configurations have not been fully exploited.RELATED PRIOR ART[0004]US 2012 / 0020485 discloses an audio signal...

AI Technical Summary

Benefits of technology

This patent describes a beamformer for microphones that helps to cancel out background noise and spatial aliasing. The beamformer uses different microphones to capture the desired signals and can adapt its sensitivity based on the characteristics of the sound sources. The goal is to create a more robust and effective beamformer for improving audio quality. The invention also explains how to select the right microphones for the desired signal based on its spatial characteristics.

Problems solved by technology

Furthermore, the first and the second beamformers may not be able to cancel the noise equally well, depending on the relative position of the microphone pair, the signal of interest and interfering noises.

As a consequence, the noise may not be suppressed equally well and / or the desired signal may not be preserved equally well.

When noise reduction is performed, there is a risk of introducing voice processing artifacts that degrades voice quality.

Images