Ordinary telephone receivers will respond satisfactorily to alternating currents at frequencies as high as ten thousand vibrations per second, but above this frequency so much of the electrical energy is absorbed in hysteresis and eddy current loss that it becomes impracticable to supply enough energy to the receiver to enable it to serve as a satisfactory source of sound waves.
Proceedings of the Iowa Academy of Science
©1920 Iowa Academy of Science, Inc.
Hewlett, C. W.
"A New High Frequency Tone Generator,"
Proceedings of the Iowa Academy of Science, 27(1), 215-216.
Available at: https://scholarworks.uni.edu/pias/vol27/iss1/32