Some system sounds (ULAW) Files Cause silence on some phones

I’ve recently discovered a really strange issue. I’ve upgraded several locations to the latest version of FreePBX, and I discovered issues with some system recordings, such as the talking clock, and voicemail menu.

If I call into voicemail (*97) with no messages, I simply hear “You have” and the rest is silent. It seems like the vm-no.ulaw file and everything after cannot be heard. I can see in the asterisk logs that it is indeed playing the rest of the ulaw files to complete the announcement.

The same thing occurs with the clock (*60). Depending on the time, sometimes I will hear the whole announcement, unless the announcement includes a 4.ulaw or a 7.ulaw, then that file, and everything afterwards is silent. Again, by looking a the logs, I can see that is playing the correct files.

The vm-no.ulaw, 4.ulaw, and 7.ulaw files are the only ones that I’ve been able to consistently reproduce the issue with, but I haven’t taken the time to try them all. I have tried downloading more recent versions of the .ulaw files from asterisk, and replacing the existing ones, but that didn’t help. Secondly I did double check all permissions, and they match the settings on the working ulaw files.

Also this issue only occurs on the one brand of phones (ascom) I’ve been through the rounds with their tech support, to no avail.