Definition - What does Sound Pressure mean?
Sound pressure is measure of the difference between the pressure caused by a specific sound wave and the ambient pressure at the same location. Sound pressure can be measured using a diaphragm that detects the vibrations caused by a sound wave. To measure sound pressure as it affects hearing, a logarithmic scale is used. The resulting sound pressure levels are expressed as decibels (dB). Sound pressure may also be referred to as sound pressure level.
WorkplaceTesting explains Sound Pressure
Sound is produced by a vibration or wave. As the energy of this sound wave passes through another medium, such as air or water, it causes a change in pressure. The change attributable to the sound wave is the sound pressure. To determine sound pressure the force of the energy wave (Newton) as it impacts a surface is measured. This surface may be a wall of air or other substance. Sound pressure may be written in units of Pascals (Pa) or Newtons per meter squared (N/m2). However, when describing sound pressure as it regards human hearing, a decibel (dB) scale is often used.
The decibel scale begins with zero representing the lowest sound that can be detected by a human being in an ideal test setting, such as a laboratory. In comparison, the sound pressure level of whispers ranges from 30 dB to 50 dB. At a sound pressure level of 100 dB, most people will begin to feel discomfort. This is because sound pressure is a force that acts upon the body as the sound wave makes impact. Excessive exposure to high levels of sound pressure can cause hearing damage.