There are many different methods of measuring sound and hearing. It can be measured by behavioral tests using an audiometer. Small measurements of hearing thresholds can be measured using electrophysiological tests. These tests include auditory brainstem evoked potentials, otoacoustic emissions and electrocochleography. Due to the advances in technology, these tests are able to be performed on infants.
The perception of sound in any organism is limited to a certain range of frequencies. Organisms only have a specific frequency of sound that they are able to hear. Hearing is normally limited to frequencies between 20 Hz to 20,000 Hz. However these limitations are not definite. The upper limit generally decreases with age. Dogs have a different rage of hearing. For example, dogs can perceive vibrations higher than 20,000 Hz but are deaf below 40 Hz.
There is equipment that is specifically made to produce sound. These pieces of sound equipment use sound measurements to ensure the proper sound is being produced. Some equipment is used to generate sound such as in musical instruments; while other sound equipment is used to enhance sound such as microphones.