Voice detection in HF/CB radio signals.

Pankaj Bamola

Other Parts Discussed in Thread: OMAPL138, TMS320C6748

Hi,

Can anybody guide me how to detect voice in HF/CB radio signals using any of the VOLIB components???

I captured the input signals from mcasp through audio in, and processed them using VAD component of the VOLIB. However, VAD doesnt seem to distinguish between noise and no data.

Actually, when i play a clean voice file(.wav) it can distinguish between silence and speech but when i play a file containing noise with speech, it doesn't detect the speech activity.

Am i using the correct approach or should i do something else.

the file that i use as input is attached (radio.wav).

Thanks & regards, Pankaj.

over 12 years ago

0 CharlieF over 12 years ago

TI__Intellectual 1605 points

Hi Pankaj,

The problem with this example is that the SNR is so low -- infact it is quite possibly negative (voice buried in noise).

The VAU bases its decisions strictly on (dynamic) evergy estimates, and as such will not be able to differentiate in an example such as this.

Regards, Charlie

0 Pankaj Bamola over 12 years ago in reply to CharlieF

Prodigy 240 points

Hi Charlie,

Thanks for your response.

What approach should be used in order to get a solution to this problem??? Is there any other alternative solution to achieve my objective??

Regards, Pankaj

0 CharlieF over 12 years ago in reply to Pankaj Bamola

TI__Intellectual 1605 points

Hi Pankaj,

This poses a very difficult problem. You will need to filter out as much of the noise as possible while preserving the low-level voice. Maybe a pitch (and harmonics) based comb filter? Either way, VoLIB does not have the filtering routines you would need.

I'm curious, what is your application?

Regards, Charlie

0 Pankaj Bamola over 12 years ago in reply to CharlieF

Prodigy 240 points

Hi Charlie,

My aplologies for replying so late. Some unavoidable circumstances kept me away from my work. If VoLIB does not have the filtering routines to help my cause, then what else could be employed or integrated with my application. My application is supposed to be run on DSP of OMAPL138 i.e. TMS320C6748.

Thanks & Regards, Pankaj

0 Pankaj Bamola over 12 years ago in reply to Pankaj Bamola

Prodigy 240 points

Hi Charlie,

I read about the implementation of Active noise filter on http://scialert.net/fulltext/?doi=jas.2007.2750.2754&org=11. It employs the LMS algorithm. Do you think this could work, or should i still try and find some alternative solution.

Thanks & Regards, Pankaj

0 CharlieF over 12 years ago in reply to Pankaj Bamola

TI__Intellectual 1605 points

That's a tough call. You may want to research this allgorithm to ensure it can handle very low (even negative) SNR's.

Regards, Charlie

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Voice detection in HF/CB radio signals.