The Raspberry Pi only has 12 bits of audio output resolution and - at least historically - has had problems with latency-related audio glitches due to Pi-specific drivers spending too much time with interrupts disabled.
I wonder if the precision would matter a lots.
Lots of lag may cause problems:-\
Couldn't you fix that with an USB sound card? My headphones included quite a nice compact one.
Raspberry Pi audio output is pretty bad though. Low quality and glitches..
Use the RaspberryPi Camera, and you've got your scanner!
Cost just went up by ~$30 if you do this...
$130 for a network connected 3D printer is still a steal.