improve youre earmuffs

[Zed]

Hi there,

I recently bought some earmuffs coz i reckon the ones I have already (1 x protector orange & 1 x osheeto noise cancellers) are a bit on the ordinary side. so i bought the new pair and they weren't much better if at all than the other pairs I have - note the manufacture was of a better build.

So I thought how can this be improved - so i pulled the protector and the new ones apart and the common link in them is that they are simply high density injection moulded plastic with some foam for comfort. thus ... ahhh..... how does sound travel through a medium ? does it travel in vacuum ? do the sound waves need atoms to vibrate thru ? does sound attenuate in dense mediums ? answers : vibration, no, yes, yes.

so I did an experiment - i injected some plain ordinary clear gutter silicon into the earpads making sure all inner surface areas had at least 1cm of coverage then placed the foam back in place and gently pressed a hollow shape that would fit my primate ears....

end result - more density in my earmuffs, thus high freq sounds attenuate MUCH more. this is good. they re a tad heavier now but I can live with this. I was so happy with the result i did the same to the new pair i bought too.

try it - you'll be pleased with the result.

[BobL]

. . . . . .
so I did an experiment - i injected some plain ordinary clear gutter silicon into the earpads making sure all inner surface areas had at least 1cm of coverage then placed the foam back in place and gently pressed a hollow shape that would fit my primate ears....

end result - more density in my earmuffs, thus high freq sounds attenuate MUCH more. this is good. they re a tad heavier now but I can live with this. I was so happy with the result i did the same to the new pair i bought too.

try it - you'll be pleased with the result.

Zed, Good idea, maybe one could embedd bits of lead in the silicone for extra absorbtion (and neck exercise!).

I agree most ear muffs are not that good although I haven't tried any new ones for the last couple of years. I occasionally use the same ear plugs that my son uses in his (very loud) band and, depending on the machine/tools making the noise, they appear to cut "sound" as much as the two pairs of ear muffs I own, with a less sweaty head/ears. The disadvantage is the on-off is not as convenient as muffs so I tend to use the plugs when I'm going to work for some time on a noisy machine.

The machines that gives me the greatest pain are angle grinders and my 100mm Makita portable belt sander, surpassed significantly by our silly garden vac/blower, which puts out a frequency that makes my nether regions squirm.

[boban]

In my job as a solicitor years ago, I dealt with hearing loss.

What I did learn was that hearing loss is associated with volume measured in dB and the length of time you are exposed to that volume. Just to be complete, age and disease also plays a part.

Even cheap muffs reduce the volume by over 20dB (based on what I've read) which means that your exposure time is significantly increased.

Generally speaking, as long as you do something to protect your ears, you will not suffer any damage to your hearing. I know how fussy Zed is about his muffs and is idea has some merit for those who really want to reduce the noise levels. My only point is that you need not throw out the cheapies based on the fear you may lose your hearing.

[Zed]

its the high freq stuff at big Db that hurts you - my ENT specialist said, and i Quote : "it only damages your hearing if its painful to listen to". thus ipods etc are safe so long as you dont play at vol 11.

thus what BobL sez is right on, angle grinders emit high freqs at big Db, up close to your head - i'm not surprised.

note that Timbecon have in thier catteldog muffs that go to 78 or so Db. they'd be good ones I think... the protector and the unnamed ones (to protect felder ) i talk about above only go to 28 Db *unmodified*... i dont know what they are now but they are greater than 28db - guaranteed....

anyway I have some tinitis so it all helps - if it helps you too, good.

cheers

[doug the slug]

...my ENT specialist said, and i Quote : "it only damages your hearing if its painful to listen to".....

thats why i dont listen to wyngers, its painful to listen to

[ozwinner]

I was fortuneate to get a job lot into the shop from a guy who worked at Melbourne aiport.
In the lot was 2 sets of ear muffs that are used on the runway apron, they are great for blocking out noise but a bit clampy on the head.

Here, Ill put them on so you can see how good they are.

See, the noise is almost totaly cancelled, even when I do this, I DONT NORMALY SHOUT WHEN I TALK BUT ITS JUST TO GIVE YOU AN IDEA AS HOW GOOD THEY REALLY ARE.

Al

[scooter]

They look nice, Al, and seem to be working well

What's that smell, though ?


Cheers...............Sean, pardon :confused:

[soundman]

Hearing loss is one of those areas where there is an awfull lot of complete and utter rubbish spoken by a lot of people who should know better.:mad: :mad: :mad:

One of the most common pieces of trash is
"If it aint hurting it ain't doing damage"

I typicaly work in an industry that has a long history of hearing damage.
I have been in situations where the SPL present was measured well above the known and accepted limits but presented no distress to my ears. I can confirm that I have had tempory hearing threshold shift on a number of ocasions.

Any body who is continuing with this particular line is completely ignorant of that which is accepted as fact in hearing protection for more than 20 years.

I am very angry that any person of "medical" standing would be still saying this.

It is known fact that you CAN get hearing damage when wearing protection inadequate for the situation. particularly in long exposure situations.

many of the cheaper muffs and most of the simple plugs are strugling to get 20dB of attenuation across the full frequency band.
So you only need to be in a situation of 115db SPL to recieve in excess of 85Db which is enough to cause damage from ongoing exposure.

Its only the high frequencies.... tell that to a friend of mine that is near deaf in one ear due to an experience with a large bass speaker and a smart $%#e roadie. there was nothing in this speaker over 250Hz.

Ipods wont hurt your hearing...... rubbish..... we are now nearing a full generation in which people are presenting with hearing damage form long term high level exposure form earphones.
These unit are capable of producing good high levels 90 to 100dB and higher at the ear, some users wear these things 12 hours a day.

I am very protective of my hearing it is my living. I daily encounter people with some form damaged hearing, some of them know only too well others are completely unaware that their hearing is poor.

I own probaly 7 different sets of hearing protection ranging from my old pair of "peltor bullseye"s down to a pair of $40 hi fi earplugs that I wear to concerts.

Cheap hearing protection is money wasted, typicaly uncomfortable, poor durability, unreliable fit and low attenuation.

My oldest pair of muffs are now about 20 years old, (Peltor) I can still get replacement earpads and liners.

For my money peltor make the best and most comfortable muffs on the market.

Excuse my rage but you only get one set of ears & when they are f#$%@D you are deaf.

cheers

[boban]

This is what I've read

What sounds cause NIHL?

NIHL can be caused by a one-time exposure to loud sound as well as by repeated exposure to sounds at various loudness levels over an extended period of time. The loudness of sound is measured in units called decibels. For example, normal conversation is approximately 60 decibels, the humming of a refrigerator is 40 decibels, and heavy city traffic noise can be 85 decibels. Examples of sources of loud noises that cause NIHL are motorcycles, firecrackers, and firearms, all emitting sounds from 120 to 150 decibels. Sounds of less than 80 decibels, even after long exposure, are unlikely to cause hearing loss.
Exposure to harmful sounds causes damage to the sensitive hair cells of the inner ear as well as the hearing nerve. These structures can be injured by two kinds of noise: loud impulse noise, such as an explosion, or loud continuous noise, such as that generated in a woodworking shop.



This is the table

Table G-16 Permissible Noise Exposures
Sound
level dBA
Duration per day, hours (slow response)
8........................................................ 90
6........................................................ 92
4........................................................ 95
3........................................................ 97
2........................................................ 100
11/2................................................... 102
1........................................................ 105
½........................................................ 110
1/4 or less......................................... 115

Exposure to impulsive or impact noise should not exceed 140 dB peak sound pressure level.

These are tested machinery noise levels from the US Dept of the Interior

Shop Equipment
Table Saw 110-115 dB
Router 110-115 dB
Band Saw 100 dB
Hand Power Saw 110-115 dB
Planer 110-115 dB
Chop-Saw 90-95 dB
Power Drill 95 dB
Grinder 100-110 dB
Steam Cleaner 95 dB

Take 20dB off the top off these levels and you can work for at least 4 hours straight without doing damage.

Of course what you are saying Soundman makes sense. I helped build what was Australia's loudest vehicle (Sound Pressure Level of 138dB) in the 90's and I doubt that any of the frequency put through them subwoofers was above 200Hz.

To be absolutely clear, most the cheapies I've seen provide a 28dB reduction. Of course that wouldn't help too much if I where to stick my head in that van. For woodwork though, the cheapies will do the job.

[NewLou]

I saw some chick on the DIY channel that was supposedly an expert on hearing she started that any medium to longterm exposure to 80Db n over would damage your ears.

They had a testing machine that picked up the Db rating of common power tools eg: Routers, Jig Saws, orbital Sanders, Disk Grinders, etc etc and guess what they all rated over 80Db.................n these babies will (^*^ )__^%)*%(^%(&^%)(^%)% your hearing.

She recommended using a combination of ear plugs n Muffs. For WIW the ear plugs consistantly offered better protection than ear muffs. I personally use the Muffs n since obtaining this information use them religiously as part of my Shed Ritual

REgards Lou

[DJ’s Timber]

I have to agree wirh Soundman, as I lost my 95% of my hearing to menigitis when i was 11 mths old. In my earlier working years I didn't wear hearing protection and I am now wishing I had. I have loss more hearing in my left ear as a result and also suffer from tinnitus which is a bl##dy pain. I also wear peltor earmuffs now and the are the best I have had.

Cheers DJ

[E. maculata]

Exactly as the Soundman said, then Boban backed with cold hard facts, buy hearing protection with an attentuation factor to cope with the job.
Peltor still make the best mass produced on the market, the H7s(green buggas, I'll bet soundys' are too) are damn comfortable and the black ones are excellent in High Dba situations.
earplugs, my personal opinion is it smaller than your elbow? no, well shouldn't be stuck in yer ear then should it .

[glock40sw]

G'day All.
When I am shooting (Ultra loud compensated handguns) I wear plugs and muffs.
Some of these guns can virtually suck your eyes from the sockets with the shockwave.

Even a lowly .22 handgun can cause pain to your hearing.
The standing safety rules are hearing and eye protection for everyone on the range. Not just the competitors.

[Harry72]

Boban that vehicle didnt happen to be the MTX Hell bus kombi?

Those db measurements from the US Dept of the Interior seem a bit suss,
Table Saw 110-115 dB
Hand Power Saw 110-115 dB
Grinder 100-110 dB
No way, the hand saw is way louder than a table saw, and thats a real quiet grinder I've seem them measured at over 120db A weighted.(at a sound off!)

[soundman]

There are a number of factors that should make us all think more conservativly.

The attenuation levels quoted for ear muffs assume the muffs and ear plugs are correctly fitted and are selaing properly.

It is very common for people to incorrectly fit ear plugs, reducing their effectiveness, some peoples ears are just so bent & twisted ( accounts for some taste in music) that it is almost imposible to fit ear plugs correctly.
Ear muffs also have their problems, many of the cheaper ones simply will no seal on certain peoples misshapen heads. If you have long hair, facial hair near your ears, wear glasses or any other protrubance about your head the muffs wont fit properly and will not perform to spec.

The attenuation figures on some of the cheaper units may be misleading, the fugure is "average attenuation" figures may drop considerably at some frequencies.

Any figures quoted by any US source ( about anything) should be considered in light of who is quoting them and what their agenda is.

Many of these figures will vary a bit depending on the specific terms of measurment. Weighting, averaging, treatment of peak content...........

The figures I have heard/seen all run round the 85 to 90dB SPL for 8 hour exposure.

Generic terms on how much certain items of equipment generate are just figures to throw arround. Their is great variation from tool to tool.

Compare a nice direct drive induction motor drop saw with a good quiet blade in an acousticaly absorbent enviroment , to an angry 2400 watt, brush motor, straight cut geared wood butchery device with a blade that rings like it was made by zildjain running in a tin shed with a cement floor:eek: . There would have to be at least 30Db difference.


On the matter of peltor
I seem to pemember they claim to have invented the ear muff ( may be ) but I remember selling peltor when they were only sold thru the fire arms industry
When they had names like shotgunner & bullseye.
Only reasonably recently have they targeted the industrial safety market.
Their muffs have always had good transient surpression and wide band attenuation, Large bore firearms work is one of the hardest hearing protection areas.
I was always struck by their comfort relative to the other offerings and the range of models.

The better muffs all have gell filled foam ear pads that reduce the need for heavy clamping forces.

If you want to feel clamping forces try on a barnd new pair of TELEX hear defender headphones, you'd swear you could be suspended by the head band.

The hard facts are that at least 30 percent of the population over 40 have some sort of significant aquired hearing loss.
The vast majority of this is not due to age alone.

CAN YOU HEAR ME POPS.... No need to shout sonny I looked after my hearing.

cheers