which unit is used to measure the loudness of sound?
Sound energy travels in waves and is measured in frequency and amplitude. The energy in a sound wave can be measured using Decibels. The Decibel Meter shows examples of things that make noise and measurements in decibels. Amplitude measures how forceful the wave is. It is measured in decibels or dBA of sound pressure. 0 dBA is the softest level that a person can hear. Normal speaking voices are around 65 dBA. A rock concert can be about 120 dBA. Sounds that are 85 dBA or above can permanently damage your ears.