Acoustic signal based Signature analysis

[akshay.joshi06]

Hello all,

I am trying to capture a signal form microphone, and comparing the captured signal with a signal stored in database. but the signal does not matches.

any help will be appreciated.

Akshay

[johnsold]

Akshay,

How are you doing the  comparison?

How do you deal with noise, phase shifts, frequency changes, amplitude changes, and time duration changes? Any of these parameters could change by a small amount making an exact equality comparison false while still keeping the two signals very similar.

Lynn

[akshay.joshi06]

Hello Lynn,

I have developed a Band Pass Filter for removing uwanted noise, also I am checking frequency and no. of peaks to analyze the signal. But I have not taken care of phase shifts and amplitudes.

The amplitude is varying as I vary the distance between the sound source and Mic.

I don't have any idea about the phase shifts.

Would you please help me out of this.

Thanks

Akshay

[johnsold]

Can you show some examples of the kinds of signals you will be measuring? Tell us what the most important characteristics (the signatures) to be compared are. How are the signals genarated? How do you establish the "standard signal?

As I said before there are many parameters to an acoustic signal. You must use your knowledge of your signals and what is important to you about them to define the comparisons.

Lynn

[akshay.joshi06]

Hello Lynn,

>>I am trying to detect some default windows sound e.g. "windows dind sound", "notification sound".

>>These sound signals are played by a desktop speaker.

>>also I have designed a band pass filter to suppress the additional unwanted signals.

       I ahve captured the signal on graph palette, Sometimes it seems to be appeared about 50%, sometimes 90 %, and sometimes 10% only of the orignal signal. I am taking care of frequencies, amplitudes and peaks in a particular signal.

      Anything else should I take care, please let me know.

Thanks

Akshay