What is the softest and the loudest sound – What is meant by Sound Level?
Sound waves are small fluctuations in the air pressure which reaches the ear. The size or amplitude of these fluctuations determines how loud the sound seems to the listener. The range of sounds is very large: the noise of a jet plane is around a million times greater than the buzz of a mosquito. Because of this huge variation, it is common practice to use a logarithmic scale to describe sounds. This scale uses a reference pressure (of P_0 = 0.00002 Pascal ) which corresponds to about the quietest sound a person can hear and then any other sound with a pressure P is compared to the reference sound by using the formula: dB = 20 log_10(P / PO) The result is known as the sound level in decibel or just dB. Because the ear has a different sensitivity to different frequencies, it is common practice to use an A-weighting system to adjust for this effect.
