Ah .... :-)

Music entertainment industry

QUOTE
Amplifying systems have become more sophisticated and powerful. One only has to think of the truck loads of equipment being carted from one entertainment venue to the next to get an idea. On a smaller scale the sound systems used in venues such as nightclubs etc, are powerful enough to cause, next to high sound levels, a sensation of vibration in the body. This has become another experience which patrons apparently wish to have when visiting such venues.

As well as hearing loss, exposure to the vibration from loud speaker systems can cause internal organs to vibrate at a much faster rate than the body trunk. This in turn may cause damage to those internal organs.

Music sound levels

Sound level surveys conducted in nightclubs, hotels and other entertainment venues found average sound exposure levels from pre recorded or amplified live music in the mid ninety to one hundred decibel range. Peak sound levels were also measured in excess of 140dB Peak (C). Often with sound levels of this magnitude the base(sic) sounds are enhanced as well and cause a vibratory or thumping sensation in one's chest.

It is not uncommon to see young people standing close to a bank of speakers to experience this sensation.

Noise control measures

As with all risk exposures in the workplace, risk management must be applied through a hierarchy of control measures, i.e. elimination, substitution, engineering and/or administrative controls, and as a last resort, or as an interim measure, reliance on protective equipment.

The control of music entertainment noise should, wherever possible, be controlled through engineering and/or administrative noise control measures.

Some examples of engineering noise control measures for loud music include:

    * install a sound limiter to ensure that the music volume does not exceed a pre-set limit. This is particularly advisable in venues where different DJs operate the sound system. Sound limiters work on the principle that a warning is given that a pre-set level is being reached. If the warning is ignored the limiter cuts out the music
    * install a sound ceiling above the dance floor. A sound ceiling consists of a structure suspended from the building ceiling with acoustic tiles and directional speakers mounted in it. This results in loud music over the dance floor but which drops by about 10dB at about one and a half to two metres from the dance floor
    * enclose or partition off the DJ booth and bar area with glass or perspex to ensure the sound levels inside these areas are within the prescribed limits

UNQUTE

:-)

DEIR clearly know the difference between dB(A) & dB(C)...