"SonomaProducts.com" wrote in message
...
but I
have never witnessed burning skin ....

how about foreskin?


Never washed my hands before... ;~)

On Tue, 15 Jun 2010 10:20:03 -0400, "Josepi" wrote:

I always wear earmuffs with my cheap sliding chop saw. They hang on the
blade cover so I have to do something with them. The ring of the blade is so
bad it actually hurts my ears.

None of my tools are loud enough to cause pain. I've been tempted to take a
sound pressure meter home to measure them, but so far haven't thought of it
when I was going to use the tools. It's full summer now, so the tools are
probably going to get a rest for a few months. :-(

I already have tinnitus quite bad and you don't want to share that one.
People think it is a joke until they lay awake at nights wondering if they
will go crazy. Sometimes I can hear it over movies rocking the house on the
600 watt Dolby surround sound 12" speakers and bass boom box shaking the
floor.

I've had tinnitus on and off for a few years. It doesn't bother me all that
much and it certainly doesn't keep me awake. Little does. ;-)

I blame most of this on small staple guns and the odd framing nailer shot
(you know the ones that just dribble out of the end?...LOL). Every so often
you get your head and ears between two joists and the shot deafens you.

Protect your ears from long or loud exposures! Unexpected ones are hard to
protect against.

My shop tools aren't loud enough and I certainly don't use them long enough to
matter, though the router is probably pushing it. What bothers me far more is
constant sinewave I listen to occasionally at work (testing audio equipment).
I can hear them for hours afterward (mostly 1kHz).

On Tue, 15 Jun 2010 10:25:18 -0400, "Josepi" wrote:

Many of our construction workers that are hearing conscious wear ear plugs
(30dB rated) along with the ear muffs for really noisy equipment.

The 60-70dB combo should get you in a better noise level for short term
exposures.

You're *not* going to get the sum of the two by wearing a belt and suspenders.
It's really about the time-weighted noise curves. You can handle high
volumes for short term exposures without recognizable cochlear damage.

Yes, but the curve certainly isn't straight. There is a point where damage is
pretty much instantaneous and there are levels were life isn't long enough for
damage to occur. ;-)

...

On Wed, 16 Jun 2010 22:47:25 -0400, "Josepi" wrote:

dB measurements do add linearly.

Not for ear protection they certainly do *not*.

It is a relative logarithmic scale that
makes calculations easy for audio and small signal people to express and
calculate.

You discount sound leakage around the ear canal. At 30dB, you're down a
factor of 1000. Conduction through the jaw bone and through the throat
passage into the inner ear become significant, which is *not* taken into
account by the muffs or plugs. The added "protection" isn't. There is good
reason there aren't products out there that are much better than about 35dB;
can't happen.

Ear plugs have reasonable leakage factored into them. The dB noise gain
figures are still added.

The bone conduction you mention is real but not a factor in cochlear damage
as the frequency range conducted is not a problem and cartilage tends to not
conduct as well.

Any sounds conducted thourh your musculoskeletal system of that magnitude
would give you more than just cochlear damage. We are talking airborne noise
here and the medium density impedance change is not conducive to
transmitting noise this way. If you are talking jack-hammer vibration then
we have a concern. Being that is not the topic of this group the rest is
just nonsense.

wrote in message
...
You discount sound leakage around the ear canal. At 30dB, you're down a
factor of 1000. Conduction through the jaw bone and through the throat
passage into the inner ear become significant, which is *not* taken into
account by the muffs or plugs. The added "protection" isn't. There is good
reason there aren't products out there that are much better than about 35dB;
can't happen.

On Wed, 16 Jun 2010 22:47:25 -0400, "Josepi" wrote:

dB measurements do add linearly.

Not for ear protection they certainly do *not*.

It is a relative logarithmic scale that
makes calculations easy for audio and small signal people to express and
calculate.

On Thu, 17 Jun 2010 21:19:01 -0400, "Josepi" wrote:

Ear plugs have reasonable leakage factored into them. The dB noise gain
figures are still added.

WRONG! Attenuation is only additive if the attenuators are completely in
series. In this case they are not.

The bone conduction you mention is real but not a factor in cochlear damage
as the frequency range conducted is not a problem and cartilage tends to not
conduct as well.

Sound is sound. Above a certain level it *will* damage the ear.

Any sounds conducted thourh your musculoskeletal system of that magnitude
would give you more than just cochlear damage. We are talking airborne noise
here and the medium density impedance change is not conducive to
transmitting noise this way. If you are talking jack-hammer vibration then
we have a concern. Being that is not the topic of this group the rest is
just nonsense.

The above is nothing more than word salad.