Audio Formats

The following native audio formats are supported:

• wav (MS wav format, 16 bit linear): This is an uncompressed sound format with a .wav extension, so the file size is very large. Sound quality will be great, but you must have adequate disk space. The recommended encoding settings are as follows:
  
  File Format Type : WAVE audio
  Sample Rate : 8000 Hz (8 kHz)
  Sample Size : 16-bit
  Data Encoding : signed-integer PCM
  Channels : 1  (mono)
  
  

• wav49 (MS wav format, gsm encoded): In this format, the file size will be small, the quality good, and it's a good choice for recordings. The file will have a .wav extension, which all Windows users should have no problems with, and users on other platforms should also be able to easily play these sound files. The recommended encoding settings are as follows:
   
  File Format Type : WAVE audio
  Sample Rate : 8000 Hz (8 kHz)
  Data Encoding : GSM Full Rate
  Channels : 1  (mono)
  
  

• gsm (raw gsm encoding): Recordings saved in this format will have about the same file size and same audio quality as wav49. It may be less well supported by client operating systems however. The recommended encoding settings are as follows:
   
  File Format Type : GSM audio
  Sample Rate : 8000 Hz (8 kHz)
  Data Encoding : GSM Full Rate
  Channels : 1  (mono)

Online audio convert tool (Asterisk playable format)

http://g711.org/