file Downloads/main\ greeting.wav
Downloads/main greeting.wav: RIFF (little-endian) data, WAVE audio, Microsoft ADPCM, mono 22050 Hz
and
soxi Downloads/main\ greeting.wav
Input File : 'Downloads/main greeting.wav’
Channels : 1
Sample Rate : 22050
Precision : 14-bit
Duration : 00:00:41.12 = 906752 samples ~ 3084.19 CDDA sectors
File Size : 459k
Bit Rate : 89.3k
Sample Encoding: 4-bit MS ADPCM
(Not going to work not in acceptable asterisk .wav format needs to be
RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 8000 Hz
soxi should see
Channels : 1
Sample Rate : 8000
Precision : 16-bit
Duration : 00:00:00.80 = 6400 samples ~ 60 CDDA sectors
File Size : 12.8k
Bit Rate : 128k
Sample Encoding: 16-bit Signed Integer PCM
)
I suggest you have sox convert it on the pbx itself
https://www.voip-info.org/wiki/view/Convert+WAV+audio+files+for+use+in+Asterisk