After they broke up the phone company in the 1980s, an advertising war began between spinoffs and new companies all trying to capture the American public’s phone service. One of the more memorable ads was the “Pin Drop” ones from Sprint.
The concept was simple, demonstrate how much better the quality of Spring phone service was by telling people you could hear a pin drop over the phone. My friend and I tried repeatedly to duplicate this “experiment” and failed (his family used Sprint).
Looking at this commercial now, I can see that it looks like they might have been using special sound equipment to boost the pin drop sounds (certainly looks sound lab-like).
It is amazing the details that you overlook when you are a kid…