Hearing threshold: Standard values & measurement
The hearing threshold, also known as the quiet threshold, varies from person to person. In general, airborne sound waves can only be perceived within certain limits, but exactly how loud different frequencies are perceived varies. The hearing threshold represents the lower limit of audible tones, i.e. the lowest sound pressure at which an auditory impression is created. The upper limit of the auditory field is the acoustic pain threshold. Accordingly, a hearing surface is created between the hearing and pain thresholds, which represents the audible range of a person.
Hearing threshold standard values/ normal hearing threshold (dB)
Which standard values can be assumed for the hearing threshold depends on the frequency. The audible range is usually between 20 Hz and 20 kHz, with frequencies between 1 and 3 kHz being the easiest to hear. A frequency of 2 kHz should therefore already be audible at 0dB with intact hearing, the values are shifted to higher levels for particularly high or low tones. Low tones of around 30 Hz and high tones in the 15 kHz range are therefore only audible from around 60 dB. Standard values for a normal hearing threshold are always subject to the influence of age and gender, as the audible frequency range decreases to an upper limit of around 12 kHz with age.
Hearing threshold measurement
The hearing threshold is measured in the tonaudiometry for defined frequencies. In addition, the measurement is carried out separately for air conduction and bone conduction as well as individually for each ear. The sounds at the different frequencies are emitted via the respective earpiece and become increasingly louder - the patient indicates as soon as they hear the sound. The results are displayed graphically in the audiogram.