Appendix E

Playing sound files during an interview

Technical requirements. Playing sound files during an interview is accomplished via the telephone system. Using the Asterisk PBX system, CallWeb offers a way to easily start and stop playing such sound files. Sound files must be saved on .gsm format. Under Linux, several sound file editors can save files in this format. Under Windows, WavPad does it too.

Operations. Start playing a sound file by inserting a CALCUL question in the questionnaire and performing the following calculation: PLAY = start_wav("sound_file") where "sound_file" is the name of the file on the Asterisk server, typically custom/some_name without extension (since Asterisk will select the most relevant file format). The sound file will stop playing at the end of the file; it can be stopped using another CALCUL: STOP = stop_wav().

Installation. Assuming Asterisk is up and running, the rest of the installation required is as follows.

  • create one Asterisk meetme room for each interviewer station; name them 6 preappended to the last two portions of the station IP address (e.g., the meetme room for station 192.168.10.128 is 610128).
  • add the following context in /etc/asterisk/extension_custom.conf and reload the Asterisk contexts:
    [cw-to-meetme]
    exten => _.,1,Answer
    exten => _.,n,MeetMe(${EXTEN}|q)
    exten => _.,n,Hangup()
    [cw-play-wav]
    exten => s,1,Answer
    exten => s,2,MeetMe(${myconf}|q)
    exten => s,3,Hangup
    exten => endmsg,1,Answer
    exten => endmsg,2,Playback(${mysoundfile})
    exten => endmsg,3,Hangup
  • create the gsm sound files and place them on the Asterisk server in the following directory: /var/lib/asterisk/sounds

Appendix E

Playing sound files during an interview

Technical requirements. Playing sound files during an interview is accomplished via the telephone system. Using the Asterisk PBX system, CallWeb offers a way to easily start and stop playing such sound files. Sound files must be saved on .gsm format. Under Linux, several sound file editors can save files in this format. Under Windows, WavPad does it too.

Operations. Start playing a sound file by inserting a CALCUL question in the questionnaire and performing the following calculation: PLAY = start_wav("sound_file") where "sound_file" is the name of the file on the Asterisk server, typically custom/some_name without extension (since Asterisk will select the most relevant file format). The sound file will stop playing at the end of the file; it can be stopped using another CALCUL: STOP = stop_wav().

Installation. Assuming Asterisk is up and running, the rest of the installation required is as follows.

  • create one Asterisk meetme room for each interviewer station; name them 6 preappended to the last two portions of the station IP address (e.g., the meetme room for station 192.168.10.128 is 610128).
  • add the following context in /etc/asterisk/extension_custom.conf and reload the Asterisk contexts:
    [cw-to-meetme]
    exten => _.,1,Answer
    exten => _.,n,MeetMe(${EXTEN}|q)
    exten => _.,n,Hangup()
    [cw-play-wav]
    exten => s,1,Answer
    exten => s,2,MeetMe(${myconf}|q)
    exten => s,3,Hangup
    exten => endmsg,1,Answer
    exten => endmsg,2,Playback(${mysoundfile})
    exten => endmsg,3,Hangup
  • create the gsm sound files and place them on the Asterisk server in the following directory: /var/lib/asterisk/sounds