Does the term busy signal refer to a tone of two combined frequencies that lasts for .5 seconds and repeats after .5 seconds of silence?

Name: Does the term busy signal refer to a tone of two combined frequencies that lasts for .5 seconds and repeats after .5 seconds of silence?
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Quizplus · Accepted Answer

A busy signal is typically characterized by a tone of two combined frequencies (usually 480 Hz and 620 Hz) that lasts for 0.5 seconds, followed by 0.5 seconds of silence, indicating that the line is currently in use.

Does the Term Busy Signal Refer to a Tone of Two