Finally, the 10 kilohertz minimum separation between stations in the United States limited fidelity to sounds much lower than the upper limit of human hearing, and the advent of high-fidelity recording equipment created a demand for high-fidelity radio.
Finally, the 10 kilohertz minimum separation between stations in the United States limited fidelity to sounds no higher than 5000 hertz, 5000 above and 5000 below the nominal frequency. This is much less than the range of human hearing, and the advent of high-fidelity recording equipment created a demand for high-fidelity radio.