The signals were not coupled, at least not in that way, and at least in NTSC. None of the bandwidth of the audio signal overlaps with the video signal. In fact, the audio signal was just a standard FM signal that you could tune into with a radio.
Maybe in those days they just played a loud noise that didn’t actually replace the sound and that was cheaper than setting something up with bandpass filters to mute it for a moment.
The signals were not coupled, at least not in that way, and at least in NTSC. None of the bandwidth of the audio signal overlaps with the video signal. In fact, the audio signal was just a standard FM signal that you could tune into with a radio.
Maybe in those days they just played a loud noise that didn’t actually replace the sound and that was cheaper than setting something up with bandpass filters to mute it for a moment.