What are the HW or sound limitations for the echo cancellation algorithm in SpeechSDK

Question

What are the HW or sound limitations for the echo cancellation algorithm in SpeechSDK

Faris Lemes 70

hi, I'm having some issues with the echo cancellation on my device, and I'm trying to use speech SDK, when I was analyzing the sounds that I record with microphone it seems that there are present higher harmonics which are 24dB less then primary harmonic, I'm not sure if this can cause the issues on the echo cancellation algorithm, and if there are some other limitations?

navba-MSFT 27,530 Reputation points Microsoft Employee Moderator

2024-06-28T08:29:31.56+00:00
@Faris Lemes Welcome to Microsoft Q&A Forum, Thank you for posting your query here!

.
Please provide the below detail:

Could you please provide more details about your use case and requirement?

Also let us know which Azure speech SDK you are using? Is it Python or javascript ?

Could you share your sample code snippet and the steps to reproduce the issue ?
Do you have any sample audio input which shows the issue ?

Could you use the AudioProcessingConstants.AUDIO_INPUT_PROCESSING_ENABLE_DEFAULT Field in your code ? and remove the AudioProcessingConstants.AUDIO_INPUT_PROCESSING_DISABLE_ECHO_CANCELLATION field if you are using ?

Does the same issue occur with speakers too ?

If you are using Microsoft Audio Stack (MAS) the here are the Reference channel for echo cancellation: https://learn.microsoft.com/en-us/azure/ai-services/speech-service/audio-processing-speech-sdk?tabs=csharp#reference-channel-for-echo-cancellation

.

Awaiting your reply.
Faris Lemes 70 Reputation points

2024-06-28T08:37:00.7466667+00:00

1.) I'm trying to make voice assistant, and the issue I get is that device can hear itself,
2.) I'm using c++ on embedded linux
3.) I can't share the code, it's under NDA, it is almost identical to the examples given by your repo

4.) I'm already using DEFAULT MAS processing flags

5.) I don't get the question; Issue is that echo cancellation algorithm is not working well. I have a device which has two microphones and one speaker. And in most cases echo cancellation does not work on it, that's why I'm asking for known limitations. I've tried to use the same code on the PC and it was working fine, so I'm trying to figure out what on HW do I have to change.
6.) I have reference channel configured.

As I mentioned in first question, I've tried to analyze the sounds recorded on the device and on the PC to compare the differences and I've noticed higher presence of harmonics on the device side in audio signal. I have THD (Total harmonic distortion) around 10%, that's why I'm asking for the algorithm limitations.
navba-MSFT 27,530 Reputation points Microsoft Employee Moderator

2024-06-28T09:55:13.8466667+00:00

@Faris Lemes Thanks for sharing the details. I will look into this and get back once I have an update.
navba-MSFT 27,530 Reputation points Microsoft Employee Moderator

2024-07-01T04:26:54.9033333+00:00

@Faris Lemes Could you please refer the below article and check if that helps?

The user experiences echo during the call
Faris Lemes 70 Reputation points

2024-07-01T07:24:20.46+00:00

I've already checked that before, and there are no hardware limitations mentioned, or any limitations, I don't have any use of the article that you attached
navba-MSFT 27,530 Reputation points Microsoft Employee Moderator

2024-07-01T09:11:11.38+00:00

@Faris Lemes Thanks for getting back. I have involved the Product Owners to look into this in the background. I will keep you posted once I hear from them.
navba-MSFT 27,530 Reputation points Microsoft Employee Moderator

2024-07-11T05:04:19.1133333+00:00

@Faris Lemes I have heard back from the Product Owners.

.

Note: I am aware that the code is under NDA. But instaed of sharing the entire code you can share just the snippet of code that you have for enabling MAS (using AudioProcessingOptions)?

You can also share that from the Private message section.

Accepted answer

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Your answer

navba-MSFT 27,530 Reputation points Microsoft Employee Moderator

2024-06-28T08:29:31.56+00:00

@Faris Lemes Welcome to Microsoft Q&A Forum, Thank you for posting your query here!

.
Please provide the below detail:

Could you please provide more details about your use case and requirement?

Also let us know which Azure speech SDK you are using? Is it Python or javascript ?

Could you share your sample code snippet and the steps to reproduce the issue ?
Do you have any sample audio input which shows the issue ?

Could you use the AudioProcessingConstants.AUDIO_INPUT_PROCESSING_ENABLE_DEFAULT Field in your code ? and remove the AudioProcessingConstants.AUDIO_INPUT_PROCESSING_DISABLE_ECHO_CANCELLATION field if you are using ?

Does the same issue occur with speakers too ?

If you are using Microsoft Audio Stack (MAS) the here are the Reference channel for echo cancellation: https://learn.microsoft.com/en-us/azure/ai-services/speech-service/audio-processing-speech-sdk?tabs=csharp#reference-channel-for-echo-cancellation

.

Awaiting your reply.
Faris Lemes 70 Reputation points

2024-06-28T08:37:00.7466667+00:00

1.) I'm trying to make voice assistant, and the issue I get is that device can hear itself,
2.) I'm using c++ on embedded linux
3.) I can't share the code, it's under NDA, it is almost identical to the examples given by your repo

4.) I'm already using DEFAULT MAS processing flags

5.) I don't get the question; Issue is that echo cancellation algorithm is not working well. I have a device which has two microphones and one speaker. And in most cases echo cancellation does not work on it, that's why I'm asking for known limitations. I've tried to use the same code on the PC and it was working fine, so I'm trying to figure out what on HW do I have to change.
6.) I have reference channel configured.

As I mentioned in first question, I've tried to analyze the sounds recorded on the device and on the PC to compare the differences and I've noticed higher presence of harmonics on the device side in audio signal. I have THD (Total harmonic distortion) around 10%, that's why I'm asking for the algorithm limitations.
navba-MSFT 27,530 Reputation points Microsoft Employee Moderator

2024-06-28T09:55:13.8466667+00:00

@Faris Lemes Thanks for sharing the details. I will look into this and get back once I have an update.
navba-MSFT 27,530 Reputation points Microsoft Employee Moderator

2024-07-01T04:26:54.9033333+00:00

@Faris Lemes Could you please refer the below article and check if that helps?

The user experiences echo during the call
Faris Lemes 70 Reputation points

2024-07-01T07:24:20.46+00:00

I've already checked that before, and there are no hardware limitations mentioned, or any limitations, I don't have any use of the article that you attached
navba-MSFT 27,530 Reputation points Microsoft Employee Moderator

2024-07-01T09:11:11.38+00:00

@Faris Lemes Thanks for getting back. I have involved the Product Owners to look into this in the background. I will keep you posted once I hear from them.
navba-MSFT 27,530 Reputation points Microsoft Employee Moderator

2024-07-11T05:04:19.1133333+00:00

@Faris Lemes I have heard back from the Product Owners.

.

Note: I am aware that the code is under NDA. But instaed of sharing the entire code you can share just the snippet of code that you have for enabling MAS (using AudioProcessingOptions)?

You can also share that from the Private message section.

Answer 1

@Faris Lemes I'm glad to see you were able to resolve your issue. Thanks for posting your solution so that others experiencing the same thing can easily reference this. Since the Microsoft Q&A community has a policy that the question author cannot accept their own answer, they can only accept answers by others, I'll repost your solution in case you'd like to Accept the answer.

.

Issue:

You are encountering issues with the echo cancellation on your device. You are trying to use speech SDK, when analyzing the sounds that you record with microphone it seems that there are present higher harmonics which are 24dB less then primary harmonic.

.

Resolution:

You managed to identify the cause of this issue which was due to a Hardware issue with higher harmonics. You had a speaker which has 10% THD, after switching to better speaker (which does not have higher harmonics) echo cancellation worked fine.

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What are the HW or sound limitations for the echo cancellation algorithm in SpeechSDK

0 additional answers

Your answer