The principle of hearing examination is open--the transmission of sound and hearing examination

3. The difference between the intensity of sound and loudness

Sound intensity: The intensity of the sound is objective and can be measured with a physical instrument (such as a sound level meter) expressed in units of energy (the energy flow density of the sound wave) perpendicular to the direction of propagation of the sound wave per unit time.

Loudness: A feeling of sound intensity that affects the strength of a person's auditory organs is called loudness. Loudness is subjective, and it depends not only on the physical strength of the sound, but also on the frequency of the sound.

When the intensity is equal, the sound of 1000 to 4000 Hz sounds the loudest. Outside this range, as the frequency decreases or increases, the loudness becomes weaker and weaker. When it falls below 20 Hz or rises above 20 kHz, it is difficult to hear. The unit of loudness is song (sone). A natural tone with a frequency of 1000 Hz and a intensity of 40 dB (feeling level) above the hearing threshold produces a loudness of 1 sone. In general, the sound (1000 Hz pure tone) is increased by 10 dB (sound pressure level), and its loudness is approximately doubled. It can be seen that the sense of subjective loudness of the human ear is not linear with the energy contained in the sound, the sound energy is increased by nearly 4 times, and the subjective sense of loudness is doubled.

Just because the human's perceived loudness and actual sound intensity are different, it is necessary to do a gas-bone conduction hearing test, and the specific hearing condition of the human ear can be understood through the gas-bone conduction hearing result.