voiceband

In electronics, voiceband means the typical human hearing frequency range that is from 20 Hz to 20 kHz. In telephony, it means the frequency range normally transmitted by a telephone line, generally about 200–3600 Hz.  Frequency-division multiplexing in telephony normally uses 4 kHz carrier spacing. The rate at which the amplitude of a signal drops off near the upper and lower limits can vary with the design of the band-pass filters.
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