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Four expedient environmental techniques to reduce music exposure along with their rationales are listed below. Depending on the musical environment (or “venue” for those who are musically inclined), some or all of these techniques may be useful, These can also be used for high-school band classes as well. (Much of this information comes from Chasin & Chong6and Chasin7 serves as the basis for the province of Ontario’s Ministry of Labour Guidelines on the performing Arts (1993).)

Speaker / Amplifier enclosures should be elevated:

Low frequency bass notes can be personified as lazy – they will always take the path of least resistance. A speaker enclosure, if in contact with the floor, will only generate mid and high-frequency energy with any significant force. The low-frequency bass notes will exhibit a lower resistance by going into the floor and are largely lost to the audience. Fig. 2. shows this low-frequency loss of energy. Sound engineers noting this loss of the low-frequency sound energy, will tend to turn up the overall level of these lower frequencies in order to re-establish the proper sense of loudness, thus unnecessarily increasing their volume. The potential for music induced hearing loss will then be greater. Elevating the speakers on stands (or even milk crates) increases that resistance for the low-frequency bass notes for the “floor” route, with the desired benefit that the output had a flatter response and is at a lower overall level.

The orchestra/band should be set back from the edge of the stage:

Placing the band back from the lip or edge of the stage will not only allow the incident sound of the band to reach the audience but also the higher frequency sound reflected of the lip of the stage to reach the audience. Sound engineers have a difficult time with room acoustics, since high-frequency energy is less at the back of a hall than lower frequency sounds. Setting the band back from the edge of the stage will allow this excess (up to 6dB) high frequency energy to be developed which will help the sound engineer’s problem. Not onyl will the music sound better, but again, the overall intensity level of the playing/amplification will be less. This translates into less potential damage for the audience and less arm and wrist strain for the musicians of stage.-Treble stringed instruments should be away from overhangs:This last environmental modification is based on the fact that higher frequency sounds can be easily absorbed by acoustically treated surfaces, because of the short wave-length that higher frequencies possess. This is more of an ergonomic strategy for violins and violas players. If placed under an overhang )such as a music pit), the higher frequency harmonic energy will be absorbed, thus causing these musicians to play hard in order to re-establish the lost high-frequency energy. Not only will the overall intensity level of this large musical section be greater, but there is a significant risk of arm or wrist damage for these musicians. Moving these musicians away from an overhang will allow the overall intensity level to be less, along with a lower risk of arm damage.

Treble brass instruments should be on risers:

The bell of a trumpet is only a “guide” for the higher frequency notes. Mid-and low-frequency notes tend to “leak” out of the trumpet from all sides. However, the higher frequency notes behave very much like a laser beam and emanate along the playing plane of the trumpet. Additionally, these same high-frequency harmonic notes are generally the most intense in the spectrum of the trumpet. Placing the trumpet on risers literally allows these higher frequency notes to go over the heads of the other musicians “down-wind.” Placing the trumpets on risers (whether it’s a high school band class, a jazz band, or a classical symphony) can reduce music exposure from this source by up to 9dB! We can also relate this phenomenon to the last issue – the raising of the loudspeaker enclosures, Loudspeakers are also directional for the higher frequency sounds. Elevating loudspeakers to near ear level will provide the musician with a better sound at an overall lower intensity level.

 

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