Issue with AMR file structure For developing an application I have to identify a region of sound. But I’m not sure if I have my basic knowledge right. I’m using AMR-NB sound clips to identify a sound region. According to my understanding AMR files have 160 samples for each 20ms (milliseconds) making it 800 sample for 1 minute. I am basing my complete dependence on this concept. Please let me know whether this is correct if not please correct me. Thanks in advance.
Actually, if it's got 160 samples every 20ms, you get a sampling rate of 8000 (you're missing a zero), which is the standard for over-the-phone voice communication. from a Google search, I couldn't find any AMR-NB specification that uses a different sampling rate.

Also, I found this line here pretty useful:


  For AMR-NB, only an “8000” sample rate and one of the following
  bitrates are valid:
  4.75k, 5.15k, 5.9k, 6.7k, 7.4k, 7.95k, 10.2k or 12.2k


Wikipedia also mentions that AMR-NB uses a 8000 Hz sampling rate, you can be pretty sure that this is the case all across the board.