Voice distortion

Hi all…
I have a scenario to investigate but i need an advice where to start…
I have one asterisk box (fully working), and in some occasion the box, via sip, transfer the call to a second box (cloned from the first box and changed ip / mac address to its eth0), that has speech to text capabilities.
In the second box i hear the reproduced playback with little distortion.A kind of noise.
I’m using ogg file format for playback.
The distortion is not so annoying but is noticeable from first box…

What audio codecs are you using ? They might be clipping high and/or low frequencies.

the second box is the clone of the first one…I have only changed ip and mac…