avaudiorecorder - iOS: Record audio below some certain frequency -


i working on app in have perform recording iphone's microphone, requirement record voice below frequency. other voice more frequency should not record.

i know has many post on this, couldn't find helpful.

i find frequency using code:- http://www.ehow.com/how_12224909_detect-blow-mic-xcode.html

but getting trouble avoid frequency being recorded.

can suggest me how or if lib/open source available. on appreciated.

thanks in advance.

first check if microphone of device can detect frequencies in band width.
second ios comes amazing framework called accelerate here can find vdsp library (digital signal processing) functionalities:

  • vector , matrix arithmetic
  • fourier transforms
  • convolution, correlation, , window generation

accelerate efficient set of functionalities, powerful , performant.
problem seems matter of filtering (mostly).
here sample apple, using fourier transform.


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