Anyone remember the in which Ella Fitzgerald shatters a wineglass with her voice, and then an identical glass is shattered by playing back a recording of Ella Fitzgerald singing the same note on a Memorex chromium-dioxide cassette tape?
It is perfectly true, Ella Fitzgerald could shatter a wineglass with her voice by perfectly hitting its resonant frequency. It is also perfectly true that Memorex did indeed shatter a similar glass with a recording of Ella Fitzgerald made on a Memorex cassette tape.
The one crucial detail they left out is that they accomplished this feat by playing back the recording at 160dB. That is louder than a gunshot. Louder than a jet airliner taking off over your head. It's roughly the same volume as standing next to a top-fuel dragster, without ear protection, as it launches down the strip. It is stunningly loud. You don't just hear it. You don't just feel it in your bones. You feel it with your entire body. It will cause immediate, permanent hearing damage.
At 160dB you can mix concrete with sound. Is it any wonder you can break a wine glass?
The decibel is a unit of acoustic power on a logarithmic scale. Every increase of 10dB represents ten times the power. A 60dB sound is not 20% louder than a 50dB sound, it is ten times louder. A 70dB sound is 100 times louder. A 160dB sound is ten thousand times louder than a rock concert. A hundred million times louder than your alarm clock.
The Krakatoa eruption of 1883 is estimated to have been on the order of 180dB. It deafened people 40 miles away, and was clearly heard three thousand miles away.
Sometimes it's not what they tell you. It's what they DON'T tell you.