The thing screamed-a high, thin sound almost past the range of audibility.
"The Terror from the Depths"
Sewell Peaslee Wright
audibility Meter of General Radio Co.
"Letters of a Radio-Engineer to His Son"
John Mills
You adjust this variable resistance until it by-passes so much of the current, which formerly went through the receiver, that the "audibility" of the signal is reduced until it is the same as for the crystal detector.
"Letters of a Radio-Engineer to His Son"
John Mills