|Instrument||Auditory danger||Hearing Protection|
|Reed woodwinds||Brass section to rear||ER-15|
|Cello/bass||Brass section to rear||ER-15|
|Brass||Other brass/horns||ER-15 vented|
|Percussion||Percussion/ high hats||ER-25|
I made up this chart about 20 years ago and it has been copied (and sometimes modified) over the years. It reminds me of the (very bad joke) when a veterinarian learns about the treatment of horses in school. It reads something like-
“if the horse has a cold, shoot it…”
“if the horse has a toothache, shoot it…”
if the horse has a broken leg, shoot it…”
Kind of gory and I would like to hope that it’s not true but the specification of hearing protection is very much like the treatment of equines. When in doubt do the same thing- recommend the ER-15 musicians’ earplugs, or one of the similar uniform attenuation earplugs on the market.
The chart above is pretty boring and I could have written it as… “recommend the ER-25 for drummers, and the ER-15 for all of the rest”. There is some truth to this, but I would like to dwell on one exception.
When it comes to exceptions, brass players come to mind. Actually when it comes to many things, brass players come to mind, but that’s another blog! 🙂 In many cases, they don’t require any hearing protection- brass players sit at the back and the sound emanating from the trumpet bell is directional (away from them) when it counts. Low and mid frequency sounds are not that directional, but it’s the higher frequency sound energy that is more intense from a trumpet. And thankfully it’s this sound that is aimed away from the trumpet player.
Life is not all roses however for the trumpet player because of the French Horn player (who actually prefer to be called a “Horn player” and not a “French Horn player”). Horn players aim their sound towards the trumpet player’s location. The trumpet player may then be subject to some undesired exposure.
The ER-15 in its normal occluded condition is not always ideal for trumpet players. Typically a small 1.4 mm vent (air hole) is required so that the lip vibration of the trumpet player won’t overwhelm them. This very small vent should be sufficient if the ER-15 is made with a sufficiently long bore since this size vent will completely get rid of the occlusion effect.
But as Shakespeare would have written, an air hole by any other name shall smell as sweet (or maybe that was about roses?). A vent (even a small vent) will compromise the low frequency protection that the trumpet player is getting from the ER-15. The difference however is small.
Normally, in the unvented ER-15 condition, the musician can be exposed 32 times as long as if they were unexposed. (For every 3 dB reduction the dose is halved… so for 15 dB reduction the dose is (1/2)5). I have done some calculations on this and it turns out that the trumpet player with a 1.4 mm vent will still achieve a benefit that they can be exposed about 30 times as long as if they were unexposed. There is a slight compromise, but that’s all it is.
Small vents in hearing protectors can be quite useful- just make sure that they are small.