Telephone Recording

Speech recordings over the telephone network are inexpensive and easy to perform. Most ISDN PC cards nowadays allow the setup of an automated speech server that steers the calling speaker through a recording session and the recruitment of speakers is reduced to offering an incentive to a prospective and maybe even remote speaker group. However, the telephone recording setup has some disadvantages, too: the recording quality is restricted to 8 kHz sampling frequency and 12 bits per sample (compressed to 8 bits), there are unavoidable technical disturbances, it is difficult to control/validate the acoustical environment, the kind and distance of the microphone and the recording setup is restricted to read, answered and dialogue speech.

The following additional features may be specified in a telephone recording setup:

• Fixed telephone network vs. cellular analog phone vs. cellular digital phone
• Home vs. office vs. public place vs. running vehicle
• Public phone booth vs. private phone
• Background noise, cross talk
• Hand-held vs. hand-free