Ways to improve the voice quality with xCORE Smart Microphone and XVSM-2000
Posted: Thu Aug 03, 2017 3:56 pm
Hi,
we selected the xCORE Smart Microphone and XVSM-2000 board for use in our project because of its noise suppression and the functionality to get the direction of arrival.
We want to do speech to text recognition using the signal we receive via USB. Therefor the qualtity of the signal must be as good as possible.
Tests with the unchanged sw_usb_audio implementation on the device now have shown the following:
- with no noise the speech to text works good even at different distances of a speaker to the microphones
- if there is constant noise directly next to the board and the speaker is 0.5m away, the speech to text fails even at low noise levels
Directly selecting the microphones to use (Button C) did not improve the result much. There still seem to be too many distortions on the signal output to detect the speech correctly. Or there might be some information on the voice signal missing. I am not sure about that.
For comparison we repeated the test with:
- smart phone
- laptop with integrated microphone (two way array, also with noise suppression)
- simple analogue microphone
The results with the smart phone and laptop were pretty impressive because the speech to text worked very well. With noise directly next to the microphones the distortions of the noise were nearly completely removed when recorded with audacity.
With the simple analogue microphone the results with speech to text were comparable to the xCORE board. A recorded signal with the analogue microphone showed really loud noise, which was a lot lower with the xCORE board, but the speech to text results were nearly the same.
That leads me to the question, what can be done to improve the efficiency of the noise suppression? We expect the result of the xCORE board to be be at least as good as the rather cheap laptop microphone.
Thank you in advance.
we selected the xCORE Smart Microphone and XVSM-2000 board for use in our project because of its noise suppression and the functionality to get the direction of arrival.
We want to do speech to text recognition using the signal we receive via USB. Therefor the qualtity of the signal must be as good as possible.
Tests with the unchanged sw_usb_audio implementation on the device now have shown the following:
- with no noise the speech to text works good even at different distances of a speaker to the microphones
- if there is constant noise directly next to the board and the speaker is 0.5m away, the speech to text fails even at low noise levels
Directly selecting the microphones to use (Button C) did not improve the result much. There still seem to be too many distortions on the signal output to detect the speech correctly. Or there might be some information on the voice signal missing. I am not sure about that.
For comparison we repeated the test with:
- smart phone
- laptop with integrated microphone (two way array, also with noise suppression)
- simple analogue microphone
The results with the smart phone and laptop were pretty impressive because the speech to text worked very well. With noise directly next to the microphones the distortions of the noise were nearly completely removed when recorded with audacity.
With the simple analogue microphone the results with speech to text were comparable to the xCORE board. A recorded signal with the analogue microphone showed really loud noise, which was a lot lower with the xCORE board, but the speech to text results were nearly the same.
That leads me to the question, what can be done to improve the efficiency of the noise suppression? We expect the result of the xCORE board to be be at least as good as the rather cheap laptop microphone.
Thank you in advance.