If you lightly tap the key, you can produce a sound with a low intensity that’s barely audible ... Humans can hear sounds in the frequency range between about 20 Hz to 20,000 Hz.

In the audible signals and alarm market, the human ear's perception of sound frequencies is crucial for designing effective products. Low-pitched signals, ranging from 50 Hz to 100 Hz, are often ...

Ultrasound is produced by high frequency vibrations beyond the range of human hearing. The frequency of ultrasound is therefore greater than 20,000 hertz. Ultrasound, like audible sounds, is ...

This is an audio recording of plant sounds. The frequency was lowered so that it is audible to human ears.