Listening with Stethoscopes through Glass Windows? Answered
I'm writing a zombie apocalypse fiction story and in one scene, one of the militia has to eavesdrop on a survivor gathering through a padded window using a stethoscope modified to fit onto a walkie-talkie earpiece microphone (the type that's along the same wire as the earpiece).
The stethoscope would be placed against the glass window. The eavesdropped survivor leader is using a loud announcement voice with no acoustic assistance, in the middle of, say, a 20m x 10m x 3m lobby. The sound would (theoretically) reverberate through the glass window and into the stethoscope, which would focus all that sound down into the mic, which is transmitted by the connected walkie-talkie to our actual listener that hears it several kilometers away through the second, receiving radio.
Notwithstanding the padded window (since the character finds a hole) and assuming the transmitted signal isn't distorted at all, how bad would the audio fidelity be for the listener? Would you still be able to understand audible speech?
Would listening with stethoscopes through glass windows even work?