GSM sound files are garbled/staticy

I have transferred a bunch of GSM files from one Asterisk box to another. The destination box works fine – ulaw files play perfectly, calls between analog lines and SIP clients are clear, etc. – with the exception of playing GSM files. Every GSM file I play, whether it is part of the default install or the ones I copied over, sounds garbled. The playback is garbled when dialing a menu item through both a SIP and an analog line.

Any ideas on what could cause this behaviour?

I’ve seen this behavior. I did not “solve” the problem, however worked around it by using .wav format sound files.