I'm looking at a job spec, detailed below. I'm perplexed as to what is being asked for.
Could someone offer a basic understanding of this material? I can imagine a solution may involve performing an FFT, setting bins outside the desired frequency range to 0, modifying phase of remaining bins, and recombining with iFFT.
but I am left scratching my head as to the purpose of this...
Application is required to:
A) input audio from external microphone jack input,
B) bandpass filter to limit audio to between 50 to 500 Hz
C) add phase delay between 150 degrees to 210 degrees (programmable via settings)
D) output resultant audio stream via speaker phone or audio jack
E) audio output volume to be calibrated to match audio input volume
A) two modes- configuration mode, normal mode.
B) in configuration mode allow user to adjust phase delay and other audio parameters, such as filter characteristics, gain and output volume.
C) in configuration mode user can select audio output via speaker phone or external speakers.
D) ability for user to disable incoming phone calls while app is running.