Simply put, decibels are a measure of the sound pressure level. We convert that into the more popular decibel scale or dB scale. In recording studios and broadcast facilities a low-noise, echo-free environment is required to guarantee speech clarity. Sound pressure level, or SPL, is a measurement of sound pressure that uses Pascals (Pa) as its unit of measurement.Excessive noise in neighborhoods can be an annoyance and can negatively affect property values.REVIEW: The unit of the bel or decibel may also be used to represent an absolute measurement of power rather than just a relative gain or loss. Another absolute measure of power called the dBk scale references 0 dBk at 1 kW, or 1000 Watts. Too much echo and reverberation can garble speech intelligibility and make music sound dreadful. Such is the case for the dBW scale, with a reference point of 0 dBW established at 1 Watt.Productivity of employees: prolonged exposure to loud environment cuts down productivity, creates stress and can lead to accidents.These rules are enforced by OSHA, as well as state and local laws. Government regulations mandate maximum acceptable noise levels in the workplace or in neighborhoods.Sharp pain and extensive destruction of the auditory nerves occurs at 140 dB.
A jet engine is at 120dB, which is a million times louder than normal speech.
For sound, its common to use decibel with a reference of 0.02 mPa (millipascals), the minimum sound that the human ear can hear.