Music and the Prevention of Hearing Lossby Dr. Marshall Chasin
/ April 30, 2007
music from what we call “noise?” Although music (for instance symphonic
music) and factory noise are considered aesthetically different, they
are both based on the principles of sound vibration (the movement of
air molecules received by the ear) and both, when excessively loud,
can cause permanent hearing loss and, at times, even lead to a ringing
in the ears called tinnitus.
Sound meter analyses
show that industrial noise and music have similar spectra (sound energy)
making it difficult to differentiate between the two. What sets music
apart is its intermittent nature (i.e., loud periods followed by quiet
moments or complete silences). During the early 1980s, Swedish researcher
Erik Borg and his colleagues demonstrated that because music is comprised
of sounds which change quickly, it allows the stapedial muscle
(a muscle found in the middle ear of all mammals) to provide ample protection
to the ear as it contracts. This intermittence is the reason why many
researchers believe that music exposure may be slightly less damaging
to the ear than an equivalent duration of exposure to factory noise.
Acting like a small automatic earplug to the ear whenever loud sounds
are heard, the stapedial muscle tightens up or contracts with the occurrence
of louder intermittent sounds and temporarily prevents these sounds
from getting through the ear successfully. Since drummers routinely
hum just prior to, and during, a loud cymbal crash they activate
the stapedial reflex and help protect themselves from hearing
loss. The same cannot be said for workers who suffer the constant onslaught
of noise emanating from factory equipment.
are less likely to experience as much ear damage as factory workers,
many studies indicate that they are still susceptible to hearing loss.
For rock/pop musicians, the incidence is up to 30%, while the portion
of classical musicians affected is as high as 52% due to longer playing
and practicing periods. This leads to the conclusion that the duration
of exposure to music and not just the music’s volume intensity impacts
the degree of hearing loss.
Traditional forms of
hearing protection have been less than ideal as they cut down higher
pitched sounds more than lower pitched ones, causing the music to sound
muffled and dull. Wearing them was like turning down the volume on the
right side of a piano keyboard but not the left. In 1988, a newer type
of hearing protection was introduced. These earplugs, called ER-15,
were custom-made for each user and promised to lower sound by exactly
15 decibels across the piano keyboard. Most musicians who use this protection
can hardly feel them in their ears. Thus, a violin will still sound
like a violin and a vocalist will still sound like a vocalist. By wearing
the ER-15 one can be exposed 32 times longer to music and suffer
no permanent hearing damage compared to someone not wearing it.
to a musician’s environment (examples below) can also be implemented
to reduce hearing loss. Most of these ideas are inexpensive to implement
and can be readily accomplished within the performance venue:
Elevate speaker-amplifier enclosures
A speaker enclosure,
if touching the floor, will only generate noticable mid- and high-frequency
energy as the low-frequency bass notes are absorbed into the floor and
are lost to the listener. The usual remedy is to turn up the overall
level of these lower frequencies, but, in the process, this unnecessarily
increases their volume and can contribute to music-induced hearing loss.
Elevating the speakers on stands (or simple milk crates) decreases the
coupling with the floor and thereby increases the low-frequency output.
This results in a flatter response that is also at an overall lower
2. Place treble
brass instruments 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. These
same high-frequency harmonic notes are generally the most intense in
the trumpet’s spectrum. Placing the trumpet on risers literally allows
these damaging higher frequency notes to pass “over the heads” of
the other musicians.
3. Position the
orchestra/band back from the edge of the stage
Sound engineers find
room acoustics challenging since there is less high-frequency energy
than low frequency energy at the back of a concert hall. Placing the
band back from the lip or edge of the stage will allow both the incident
sound of the band and its higher frequency sound (up to 6 dB) to be
reflected up off the lip of the stage to the audience. Not only will
the music sound better, but the overall intensity level of the amplification
will be decreased. This translates into less potential hearing damage
to the audience, and less arm and wrist strain for the musicians.
4. Keep treble
stringed instruments away from overhangs
If violins and violas
are placed under an overhang (such as a music pit), the structure will
absorb their higher frequency harmonic energy forcing the musicians
to play harder in order to maintain their volume. This not only
increases the overall intensity level of this large musical section
but also increases the string musicians’ risk of arm or wrist damage.
Moving them away from an overhang lessens their potential for hearing
loss and other work-related injuries.