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How to eliminate feedback in ADAU1701

Hi everyone,

I am using ADAU1701 for the application Voice Processing. Everything is working fine. But our problem is while speaking via microphone it is fine, but when it is in normal position we are getting whistle kind of sound.

How to eliminate the feedback which is coming from microphone with speakers. Please help to resolve this problem.

I have attached our setup.

Regards

Vishnu

attachments.zip
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  • Hello Vishnu,

    Thanks for the video link. Now I understand better.

    Can you educate me on how these things function?

    It is clear to me that they drive a low frequency tone to excite a sound wave, with harmonics, that the user can manipulate with their mouth and tongue, etc., to produce speech. Is there a microphone that is picking up the sound and amplifying it out of a speaker?

    So the stimulus sound is being sent out of a driver and the microphone is picking it up and amplifying it?
    Is this stimulus being produced inside of the DSP?

    How accurate is the transducer? Does the transducer have a lot of distortion?

    The reason for the questions is that the NLMS filters need to know the stimulus signal to attempt to remove it from the output. If the stimulus signal in the DSP is not very close to the actual signal being heard then it will not be very effective. For instance, if the transducer is a poor quality piezo-electric element that produces a lot of harmonic distortion then the output signal that is driving the transducer is not the same as what it coming out of the transducer. So using the drive signal the DSP is producing will not be an accurate copy of the actual signal. So we would have to be creative.

    Is there a controller in your system that could boot up a DSP?

    Dave T

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  • Hello Vishnu,

    Thanks for the video link. Now I understand better.

    Can you educate me on how these things function?

    It is clear to me that they drive a low frequency tone to excite a sound wave, with harmonics, that the user can manipulate with their mouth and tongue, etc., to produce speech. Is there a microphone that is picking up the sound and amplifying it out of a speaker?

    So the stimulus sound is being sent out of a driver and the microphone is picking it up and amplifying it?
    Is this stimulus being produced inside of the DSP?

    How accurate is the transducer? Does the transducer have a lot of distortion?

    The reason for the questions is that the NLMS filters need to know the stimulus signal to attempt to remove it from the output. If the stimulus signal in the DSP is not very close to the actual signal being heard then it will not be very effective. For instance, if the transducer is a poor quality piezo-electric element that produces a lot of harmonic distortion then the output signal that is driving the transducer is not the same as what it coming out of the transducer. So using the drive signal the DSP is producing will not be an accurate copy of the actual signal. So we would have to be creative.

    Is there a controller in your system that could boot up a DSP?

    Dave T

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