Posted on 10/31/2014 4:41:50 AM PDT by LouAvul
+1. Best money I've ever spent.
I do not believe that is true. Each step takes a cut out of the amplitude of the sound wave. If you wear ear muffs and ear plugs, it is far more protection than just one or the other. It may not be 100% additive, as the reduction of the plug is from a lower amplitude than the ear muff attenuated from, but it is certainly a significant reduction.
Maybe your data is more recent than my own? I read that if one wears plugs and muffs that he takes the highest NRR of the two, then adds 5. If the plugs are rated at 25dB and the muffs at 20dB then the wearer has protection of 30dB. Is that not accurate?
No way you are getting the full sound level of a gun as long as you are behind it. Best ear protection for shooting is:
http://www.ebay.com/sch/i.html?_nkw=noise+cancelling+earmuffs
Remember the dB scale is log. A 10 dB reduction is a significant reduction in sound level.
I found a place that sells sample packs of a bunch of different types of disposable ear plugs.
http://www.earplugstore.com/unfoamtrialp.html
This is an easy way to determine which plug works best for you.
I can attest to this. I ran heavy equipment and armor for years and wore both plugs and muffs, but the subsonic noise was not filtered. It is virtually impossible to reduce transmission as it travels through the skeleton. I don’t know of anything that will prevent loss with long term, constant, low frequency exposure.
The other problem was the duration of exposure—10-12 hour shifts with a constant hazardous level. We were given a “quiet” week off prior to occupational testing, and still failed every test. I once had a tech who was very concerned until his boss asked my what my job was and then replied,” you’re fine.”
At 50, my heating has become a trial, and hearing aids are only a stopgap. You can’t recover from permanent nerve loss.
Use both muffs and plugs. Intermittent noise generated from gunfire or other acute sources can be muffled. Electronic protection is available and worth the investment if you have long term requirements. The military has finally mandated it, but only for certain fields.
A big part of the problem is that limits are set based on the human ear perception. At the bottom of the page in the last link I sent was more info about dBA and SPL, etc... I’d follow through on some of the other links there, you are sure to find more info.
Bottom line is you will have to determine based on multiple sources what is most likely damaging on a per frequency basis and add some room for variance, err on the side of caution and move on.
Actually, for the most part a bass player will need a lot more than 3X the power of a guitar player in order to keep up with drums and guitar on stage while maintaining good tone. This is due to how amps are rated (most power ratings on all amps including bass amps) are based on 1000Hz. Most bass signals are well below that and the corresponding amps’ 3dB rolloff points are well above where the fundamental and resonant frequencies of bass guitar reside. Guitar harmonics are much higher frequency than bass are as well.
When I play with the band I usually gig with, we have two guitars (both are using about 65 to 100 watt rigs) a harmonica, a keyboard, a drummer, about 3 people singing and usually someone playing percussion of some sort. When I use my 400 watt amp with a 2x10 cab I am able to keep up well enough on stage, but I definitely have to be put in the mix through the PA to cut through the rest of the “house”. I generally have to run at least half power if not 2/3 to manage that though.
In order to drive low frequency sound, you need a lot more current, which is why you have to have a much higher wattage bass amp to keep up with a much lower wattage guitar amp. 400W at a minimum of 1/3 - 1/2 power will keep up with a band on stage (generally), but will need to be put through a PA in larger settings or night club volumes. because the human ear is more sensitive to 1-4KHz, the guitar is more suited to being heard well by the very nature of the frequencies it outputs as well.
110 Hz is the frequency of vibration of the A string on a guitar. The A above that (second fret on the G string) is 220 Hz. The next A (5th fret on the high E string) is 440 Hz, which is the orchestral tuning A. (The guitar A string plays the A normally written at the bottom of the bass clef. In guitar music, however, it is normally written an octave higher.) We can hear sounds from about 15 Hz to 20 kHz. The lowest note on the standard guitar is E at about 83 Hz, but a bass guitar can play down to 41 Hz. The ordinary guitar can play notes with fundamental frequencies above 1 kHz. Human ears are most sensitive to sounds between 1 and 4 kHz - about two to four octaves above middle C. Although the fundamental frequency of the guitar notes do not usually go up into this range, the instrument does output acoustic power in this range, in the higher harmonics of the most of its notes.
Finally,
Mark bass as well as a number of other boutique style bass amp makers have gone to class D amps, which will allow a 400 - 800 watt bass amp head unit to be in the neighborhood of 10-20 pounds vs. the horse that I use for 1200 watts being 60-70 pounds outside of a rack. Solid state amps are obviously much lighter than tube amps, hybrids somewhere in between (which is what my 1200 watt amp is). The 400 watt AMP brand head that I play through is about 20 pounds.
I used ear plugs religiously during my entire career. I had one incident, off duty talking to a buddy when somebody popped the hatch while a harrier was taking off. My right ear has been ringing for about 25 years and I lost about a third of the hearing in that ear.
Something to remember the Navy by.
Years ago on FR I read about a guy who spent WWII as an AA gunner in a gun tub on a ship. After the war he went to the VA because of his hearing loss and ringing. They checked him out and said it was a natural condition of aging. He was 25.
Guys who have been aboard a Battle ship as she fired her 18’s (or 16’s) have said that the those who have not experienced it can never through mere words alone comprehend the moment.
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