Great info, keep the ear plugs ready - I'm rambling on again.
Shots are the obvious source of noise but it isn't the only one, think lawnmower, chainsaw, blender, meat grinder, vacuum cleaner, anvils, drills... all their racket accumulates throughout life like pennies in a piggy bank. Eventually it becomes something real.
I think hearing protection works on two fronts. 1) performance and 2) actual time in use. Unfortunately, top performing stuff, by its nature and its cost is going to be applied mostly in specialized situations while with all the buzz we forget about the vacuum cleaner.
So, I want to make sure we don't sidestep the cheap and easy throw away hearing protection. If they are not inserted to top performance, so what, at least they get more covered uses: the foam plugs are easy to buy in bulk and I keep a good supply of them everywhere, in the Jeep, in the kitchen, in the desk drawer, in the garage by the lawn power equipment. Always enough for me and for my friends. Along with inexpensive knitted gloves and emergency stashes of chocolate, those items are the little niceties of life that are great sharing with friends and kids. It's about comfort and good habits.
Where there are hammers and anvils there should also always be sets of earmuffs. Scatter them around. It's cool.
And now, to share a vision about hearing tests
We all knew my father had become hard of hearing. Audiology tests showed figures and numbers attesting to it but what did he or did he not actually hear? Unlike vision, the blurred perception is not obvious to confront by just stepping into it. Thus, I wanted to see the audiology test for myself... and I have a piano... whoo hoo.
The piano is about the best physical representation of human hearing, from left to right we have about seven octaves of sounds to hear - made-to-measure sounds custom-fitted for our human ears. The lowest is the A to the left rumbling at 27.5 Hz - and lower than that, the human ear does not go. It seems unbelievable and the reason the piano keys stop right there is precisely because we would not hear anything further to the left. It's even hard to imagine that we can't. No faith? Perhaps a local church near you has a big organ. Normal hearing falls silent a little beyond the range of the 16 ft long pipe... but... next... comes the 32 ft long pipe at a frequency of 16.4 Hz and that would be the C beyond the left end of the piano keyboard. One church here in my town has a true full blown set of live metal pipes that go down to the 32 ft long one, while the neighbor across the street only has a simulated electronic version of that, for the same effect: the 32 ft implement makes no sounds at all - beyond the same last A as on the piano, we can't hear them. All you get from close by is the huffing of an out of puff blower and you can't tell if the sound is getting deeper or not.
Why? Why not? Bigger is better. The Atlantic City convention hall has a live 64 ft pipe and... us... we have big bore double guns. The interest in the deep frequencies is that when played with other audible sounds they get the harmonic frequencies to kick in for resonances we do hear and feel deep within as they rattle the windows of our soul.
Organ pipes along with the frequencies at which they vibrate get chopped by half every time we rise one octave of seven steps, or actually twelve half steps. Going up the seven octaves of seven steps, thus, the first C we encounter from the left is a 16 footer, the next one is only 8 ft long anymore, 4 ft next and we reach middle C at 2 ft. Now, here is an answer to a riddle that must have puzzled most of us. Do guns make audible noise? Well, duh, common barrels come in at 24 inch long - a ubiquitous 2 feet, and thus, within the range of churchly music our double guns shoot for middle C.
Or something like that. A 32 inch barrel is the G before middle C, 28 inch is about an A, 26 about a B, 24 the middle C and 20 inch rings in a D sharp. Bang bang it's music. At least to me.
Frequency wise, the first deep A from the left is 27.5 Hz, the next one is 55Hz, then 110 Hz, approaching middle C we have 220 Hz, then 440, 880, 1760, 3520 and then the keyboard ends... Just like that... although human ears can hear further to the right, young kids in particular, and normally we can hear from about two to four octaves beyond the right side of the piano. To find the frequency of any particular note, just add about 5.95 % for each half tone from the nearest A, do it twelve times and you'll find the next A an octave up. The percentage comes from the twelfth root of 2 because we double the frequency number in twelve steps, and 2^(1/12) = 1.05946.
Enough of the music?
I can do our own in home audio test with my father. I play the notes on the piano and without looking he tells me if they are higher or lower. At some point, he can't tell anything at all beyond the sounds of the mechanism. Simple. The first time, I was surprised that without really knowing what I was doing, my test produced the same sound frequency limit he had on his diagnostic chart. What really surprised me is how much he couldn't hear anymore: much of the last two top octaves on the piano where a blur to his ears, I thought it was very graphic and about as easy to visualize as the haze of impaired vision.
Too bad our music has to be played with the ear muffs on.
