Kynnysäänenvoimakkuus

Kynnysäänenvoimakkuus, often translated as threshold of hearing or auditory threshold, refers to the minimum sound pressure level that a person can detect under specific conditions. This threshold is not a fixed value but varies significantly between individuals and even for the same individual depending on factors such as frequency of the sound, duration of exposure, and the listener's age and hearing health.

The standard reference for auditory threshold is typically measured in decibels (dB) and is often defined at a frequency of 1000 Hertz (Hz), where the average young, healthy human ear can detect sounds as low as 0 dB. This 0 dB is a reference point, not the absence of sound. Sounds below this threshold are generally inaudible.

Measuring kynnysäänenvoimakkuus is crucial in audiology for assessing hearing ability and diagnosing hearing loss. Audiograms, which plot hearing thresholds across a range of frequencies, are the standard tool for this purpose. Understanding an individual's auditory thresholds helps in fitting hearing aids and determining appropriate assistive listening devices.

Environmental noise levels are also often compared to this threshold. For instance, a quiet library might have a background noise level of around 30-40 dB, while a busy street could reach 70-80 dB, well above the threshold of hearing. Prolonged exposure to sounds significantly above the threshold, particularly those above 85 dB, can lead to noise-induced hearing loss.