Threshold of Hearing


Also found in: Acronyms.

threshold of hearing

[′thresh‚hōld əv ′hir·iŋ]

Threshold of Hearing

 

the minimum sound pressure level at which a sound of a given frequency can be perceived by the human ear. It is customarily expressed in decibels by taking as the zero level a sound pressure of 2 X 10-5 newton/m2, or 2 × 10-4 dyne/cm2, at a frequency of 1 kilohertz (for a plane wave).

Figure 1. Standard threshold of hearing of a sinusoidal signal in relation to frequency

The threshold of hearing varies with the frequency of the sound (Figure 1). It is higher for a given sound when the sound is accompanied by noise and other acoustic stimuli (seeSOUND, MASKING OF). This higher value is maintained for a certain time after the interference stops; the threshold then gradually returns to its original level. The threshold of hearing may vary for different people and at different times for the same person, depending on age, physiological condition, and training. It is usually measured by audiometric methods.

REFERENCE

Beranek, L. Akusticheskie izmereniia. Moscow, 1952. Chapter 4, sec. 4. (Translated from English.)
Rzhevkin, S. N. Slukh i rech’ v svete sovremennykh fizicheskikh is sledovanii, 2nd ed. Moscow-Leningrad, 1936. Chapter 1, sec. 2; ch. 2.
References in periodicals archive ?
Relationships between speech rate intelligibility, hearing loss, and ear-aided threshold of hearing impaired children were investigated as well.
Zero dB refers to the softest sound we can hear, the threshold of hearing, while an increase of 120 dB would be getting uncomfortable.
Zero dB is roughly the threshold of hearing for young people at a frequency of about 4,000 Hz where ears are most sensitive.
On page 102, the threshold of hearing is said to be around 10 watts per square meter at 3,000 Hz for people with acute hearing.
Loud 70 Average Restaurant, Noisy Office Comfortable 60 Average Conversation at 3 ft Faint 40 Library, Quiet Street Very Faint 20 Whisper 0 Threshold of Hearing Table 2.
p]) -- The ratio, expressed in decibels, of mean-square pressure to a reference mean-square pressure which by convention has been selected to be equal to the assumed threshold of hearing.
Average threshold of hearing was taken and greater than 25 dB was used as an indicator of hearing loss.

Full browser ?