title: FFMPEG:Adding beep sound to another audio file in specific time portions
body: <p>I've a scenario in which I need to modify certain portions of audio file.Currently,I'm able to add silence to the audio file at specific portions through FFMPEG audio filter -af.But is there something that can replace particular portions of audio with beep sound and the duration of the file should be same after the process? </p>
  
  <p>Eg: Input.wav,I want to add beep of 10s-15s(i.e.,5 seconds) to the file  </p>