One More Way To Prevent Deafness, Or A Very Silent Movie
Today’s movie theaters offer viewers the effect of almost total presence – this is not least of all due to the multi-channel audio playback. But in most cases, the sound power is so intensive that can affect human health.
Committee on Health in the state legislature of Connecticut, USA, began reviewing the draft law that considers the maximum power of sound in all theaters of the state should not exceed 85 decibels.
This is very little compared to the sound pressure, which is being released by the cinemas’ speakers currently.
Just to compare: 85 decibels is the power of a conventional alarm clock sound, “beeping” in the morning on the nightstand or dresser in the bedroom. Operating electric hammer drill emits sound power reaching 90-95 decibels, passing-by truck emits approximately 70-80 decibels maximum. Common household hair dryer emits sound force of about 100 decibels, and the crying baby “calls” to its parents with the sounds having loudness of 90 to 110 decibels.
The standard of 85 dB for cinema has been recommended by the National Institute of Occupational Health of the USA.
The law aimed to limit the intensity of sound in movie theaters has been introduced by Senator Carlo Leone, who claims that a lot of the residents of the state address him with complains about too loud sound in the cinemas, which prevents the perception of films, and may intensify the severity of hearing loss.
A group of independent experts has performed measuring of power of the audio stream in a number of the movie theaters throughout the United States. The findings of this study have shown that in many episodes of different movies the sound intensity was 110 decibels or exceeded this value.
Such levels of sound can cause acoustic trauma, prolonged exposure to loud noise (> 90 dB) results in the inability to hear sounds of high frequencies (exceeding 4000 Hz). For reference, the normal hearing frequency range is 20 to 20 000 Hz.
The representatives of the association of theatre owners in USA (Motion Picture Association of America), who fear reducing the number of moviegoers, especially among young people, on the quiet, have already appealed against the adoption of such a law and announced this new law to be completely unnecessary.
In addition, the owners of the movie theaters claim that this law is “discriminatory”, because it does not contain any restrictions on the volume during rock concerts, sporting events and the like.