Facts about Sound
- Sound is vibration causing pressure. It is measured in in decibel (dB) and frequency (Hz).
- dB is a logarithmic scale. For example, an increase of 3 dB doubles the sound pressure level. The difference between 0 dB and 120 dB, which is the pain threshold, is around 100 billion times.
- A small increase in dB represents a gigantic increase of noise exposure risk.
- Frequency is the number of oscillations per second. Humans can hear frequencies between 20-20 000 Hz.
- The most common sounds, like that of human speech, are found in the mid- to high frequency range (500-4000Hz). This is where human hearing works best, but it is also where your hearing is most sensitive to overexposure.