Active noise suppression muffs?

[Ratbag]

I've been required of late to work in an industrial environment.

It's loud. Extremely so. Despite supposedly having ear defenders supplied, I've so far had to supply my own. The only good ones I have are 3Ms with an integrated FM radio, which are forbidden, even with the radio off! My other ones just arent "quiet" enough to be able to hear speech.

Anybody had experience with any "active" noise supressing/cancelling type muffs that have a battery type circuit to reduce machinery noise. It's in a poultry slaughterhouse, which has multiple machines, motors, pumps, production lines and the like creating a constant noise.

From what little I've been able to glean from the interweb, most of these active defenders guard against loud intermittent noises such as gunshots. Does anybody know or have experience of the type that suppresses noise over a preset db. threshold, but allow lesser levels (i.e. speech) through?

Any personal experiences, or a guide to further reading or research sites would be greatly appreciated. I should also add that whatever is recommended should be sufficiently robust to withstand moderate levels of heat, humidity, water splash and freezing cold in operation.

[FenceFurniture]

No experience Ratty, but following with interest. I think they are also known as "noise cancelling" if that helps with any searching.

[Evanism]

My hearing is very sensitive... Can hear Mosquitos and cans of coke bubbling from across the room. My wife thinks I'm autistic and intolerant.

These below don't have radio or active noise cancellation, but they are so amazing one feels completely deaf. It's a strange scenario when you can't hear a person talking to you, or when working on something loud (thicknesser) all you hear is your own heartbeat.

I have these: http://www.amazon.com/gp/product/B00009LI4K/. The 3M Peltor H10A. They are said to attenuate 35db's.

They were recommended by a guy who works on planes at an airport.

Bilsom Thunder T3 are said to be the best, but you can't get them here.

Sorry it doesn't answer your question, but they do appear to be sold at all the worksafe places.

[FenceFurniture]

These below don't have radio or active noise cancellation, but they are so amazing one feels completely deaf. It's a strange scenario when you can't hear a person talking to you, or when working on something loud (thicknesser) all you hear is your own heartbeat.

This does bring up another safety issue - where you can't hear what's going on behind you (and need to jump out of the way pronto).

The local men's shed captain says he doesn't wear muffs because of this reason....but then he goes and uses a router screaming in his ears, which I think is madness. There is an argument that says you can actually hear what's going on elsewhere better when your local noise is attenuated, but I've never tested it (makes some sense though).

I have a feeling that those Peltors would knock out all noise, and so this could be a consideration. Maybe noise cancellers don't do that as much.

Ratty, the other thing you could do is use silicon putty available from a Pharmacist. I'm like Ev with my hearing - very sensitised, and SP allows me to sleep in fairly noisy situations (as long as you can put up with the sound of your heart and breathing.

You could wear the SP underneath the current ear muffs and it will make a substantial difference. Quick, cheap and available.

[BobL]

Anybody had experience with any "active" noise supressing/cancelling type muffs that have a battery type circuit to reduce machinery noise. It's in a poultry slaughterhouse, which has multiple machines, motors, pumps, production lines and the like creating a constant noise.

My hearing is poor (too much exposure to loud music in the 1970s) so I have taken a great deal of interest in ear protection during the last decade or so. During this time I've tried and had a number of muffs including noise cancelling phone by Jabra, Sony Bose, and Senheiser. I use them mainly for air travel but I did try some out in my shed and some with my chainsaws. NONE of the noise cancelling muffs were as good at reducing noise as the passive Peltor H10A/B muffs. I have 4 sets of these muffs and the only ones I would replace these with would be for something like this.
http://solutions.3m.com.au/wps/porta...gl55KQTJS2Z2bl

A couple of things worth knowing about ear muffs.

Like DC air flow rates the specifications provided by manufacturers are pretty dodgy. One way to assess if a manufacturer knows what they are doing is if they can supply a frequency response curve for their products, if not then they don't really know what t hey are doing. Unless your head is inside something like a deep sea divers helmet it is physically impossible to reduce sound by more than ~36dB - this is because the noise bypasses the ear and travels thru skull bones to the ear. Hence any claims to more than about 30dB NRR unless a frequency response curve is provided should be treated with considerable skepticism.

Standard consumer type noise cancelling are not appropriate for the workplace. Most are made of brittle plastic, don't come apart for cleaning and cannot handle sweat well and are just not physically robust enough. I would not use any unless they have a strong connection between the muffs . Some chew thru batteries quite quickly and most simply do not clamp onto the head strongly enough to adequately reduce outside noise e.g. those that sit on top of the ears are not able to reduce noise (see above). The muffs must completely cover the ears and clamp down moderately hard to be effective.

This is where the issue of comfort V effectiveness comes in - muffs that you can wear for hours that are moderately effective MAY be more useful in the long run compared to muffs that are highly effective but uncomfortable. I have worn my passive Peltors on planes and they work brilliantly but after an hour or so they are uncomfortable so this is why I use consumer muffs on planes. Initially I used Jabras but then these became unavailable I bought a pair of Senheisers. I found the Senheisers were not quite as effective as the Sony's but were more comfortable on me. The problem with the Senheisers is they chew through batteries and five years on the padding has started to come apart. My favourites in terms of effectiveness were the two pairs of Jabras - very comfortable - but they eventually broke

From what little I've been able to glean from the interweb, most of these active defenders guard against loud intermittent noises such as gunshots. Does anybody know or have experience of the type that suppresses noise over a preset db. threshold, but allow lesser levels (i.e. speech) through?

Any personal experiences, or a guide to further reading or research sites would be greatly appreciated. I should also add that whatever is recommended should be sufficiently robust to withstand moderate levels of heat, humidity, water splash and freezing cold in operation.

In the end you will basically get what you pay for. Muffs that come apart and can be washed will reduce the transfer of bugs. If you stick to a reliable manufacturer like 3M that can supply a frequency response and spare parts then you should be better off than buying a budget pair from a manufacturer that goes out of business tomorrow.

Something like this might suit your needs
http://solutions.3m.com/wps/portal/3...3786499&rt=rud

[Robson Valley]

I can only suggest that you talk to a bunch of serious trap shooters.
While noise-cancelling muffs with added foam sheets may be effective,
there is nothing that can cut high-level and leave speech.
Sorry, nothing

I can't hear over 4k. Volume is a bit of an issue.
What you say, loud enough and clear enough, does not match words in my head.
Aural cognitive disorder. I need closed-captioned TV to watch.

I have big satellite TV for visitors, may watch 2 hr per month.

I wish you well.
The audiologist got no further than to claim that it was both gunshots and explosions
over the years that rotted my hearing.

[BobL]

I can only suggest that you talk to a bunch of serious trap shooters.
While noise-cancelling muffs with added foam sheets may be effective,
there is nothing that can cut high-level and leave speech.
Sorry, nothing .

Depends what you mean by "cut" and what sound are involved.

If you mean by cut completely there's nothing short of a vacuum that cuts out sound, so some gets trough no matter what is used.

If you mean "reduce sound" then the high level noise reduction muffs with an band gap electronic filter will still reduce sound levels and leave enough speech frequencies to get through. It's not like all the sound from speech gets through either.

The problems come where the noise frequencies match the band gap filter frequencies but in the case of machinery this is usually much less of problem. Of course the sound won't be cut as much as i for when no filters are are used.

[BobL]

. . . . . Ratty, the other thing you could do is use silicon putty available from a Pharmacist. I'm like Ev with my hearing - very sensitised, and SP allows me to sleep in fairly noisy situations (as long as you can put up with the sound of your heart and breathing.

You could wear the SP underneath the current ear muffs and it will make a substantial difference. Quick, cheap and available.

I can understand why you would use ear plugs for sleeping but I rate ear plugs like dust masks, use them after everything else has been done to reduce the problem, including in the case of sound using ear muffs. So my chainsaw use involves ear muffs and plugs, mainly because I wear glasses and the muffs do not seal around my ear quite as well as without glasses.

In a serious study done a few years ago it was found that even trained audiologists could not consistently fit ear plugs to obtain the same level of hearing protection as ordinary folks could obtain using muffs. Plugs need to be carefully fitted every time they are inserted so problems arise when they need to be taken in and out in a hurry on a regular basis. Muffs aren't perfect either but on average they are better than plugs.

[FenceFurniture]

In a serious study done a few years ago it was found that even trained audiologists could not consistently fit ear plugs to obtain the same level of hearing protection as ordinary folks could obtain using muffs.

What I like about silicon putty is that the user can mold prod push it into shape until they get the desired result (which an audiologist can't really do because they are not hearing the results).

It's very important not to have waxy ears when fitting otherwise they won't stick in place. The putty does harden after a while, but as i recall i could get a month or so out of a pair.

It's a pretty serious reduction of noise - much better than those yellow stick in things which I've always found to be next to useless.

Edit: To be clear, I'm suggesting Ratty can use the SP in conjunction with his current ear muffs. I'd be confident that will reduce the sound pretty substantially.

[Ratbag]

Thank you all for the suggestions. It's much appreciated.

I must admit my hearing isn't the best anymore.

Like many others, just too many 70s pub bands, too drunk to notice how loud they were (the Angels were the loudest I think). Chainsaws, motorbikes and assorted machinery, the worst of which was probably air drilling with an Ingersoll Rand. Plus playing around in the Cut-lunch Commandos (6RAE). We sawmilled, blasted, crushed rock, built roads & bridges, operated dozers etc. all without any protection. Young, stupid & bullet-proof. Worst of all was helping out with the drop-shorts (artillery). 105mm howitzer live fire drills with only a bit of cotton wool flocking in the ears! If you can be made to feel nausea from the live fire concussion, I'm sure it's not doing the hearing much good.

My ears are very waxy. Always have been. A legacy from my father, who suffered punctured eardrums as a child from rough attempts to syringe the wax out! Having experienced his pronounced (but not profound) deafness through my childhood should have taught me better. Nevertheless, I'll jealously guard what of the faculty still remains. I don't think inner ear protection would work, or be very hygienic.

So it's off to do the rounds of workwear retailers on Monday morning after work to see what's available. It seems that the 3M/Peltor range are more effective than most, & from what you're saying the jury is still out on the effectiveness of active noise suppression.

Over the past few years my wife used to fly in & out of various refugee detention centres regularly. The long haul flights to Xmas Is., Northam and the Gulf were all made much more tolerable when I bought her a pair of Bose Quiet comfort headphones. My thinking was that if this sort of tech. was combined in a proper quality set of ear defenders the result could (should?) be good. I need to hear not only speech, but the more subtle sounds of changes in pitch of machinery to give me the tell-tale that not all is right. Somehow, this currently tends to get drowned out by the sheer volume of noise emanating from the assorted machines.

[BobL]

The value of being able to hear machinery came home to me a year or so back.

I was grinding and drilling so had ear muffs and face shield on.
I was using a near new MT bit that slipped out of the MT and I reached up and turned off the DP switch - well I though I had switched it off.
I then picked up the bit and rammed it back up into the MT.
Fortunately the DP was on a slow speed as when in grabbed the bit it took a bit of skin off but it could have been a lot worse.

[Bob38S]

Check out this mob.

Moulded to to your ears therefore unique and a perfect fit. Used by shooters, racing car drivers and rock band members. They really work in that you can still hear but loud noise is cut to a very comfortable level. With these ear plugs it is also very easy to wear a hat or helmet and they are much cooler if you are in a hot environment and you don't sweat as much as you do around the ears when wearing standard type earmuffs.

http://www.earmold.com.au/Insta-Mold...-products.html

[cava]

This is a good and valuable thread.

I have a set of Peltor H10A ear muffs and notice that, when I am cutting the grass, they slowly slip and let more noise in than when I started. Generally I do not notice this until after a few hours.

Whilst good, I think that I may have to use plugs with them.

[BobL]

This is a good and valuable thread.

I have a set of Peltor H10A ear muffs and notice that, when I am cutting the grass, they slowly slip and let more noise in than when I started. Generally I do not notice this until after a few hours.

Whilst good, I think that I may have to use plugs with them.

I agree they do ride high and there is no vertical adjustment.
I wear mine in conjunction with a full face Armadillo shield so they don't slip down and they help hold the shield on.
I have used them without the shield and I gaffer taped a small piece of foam to the underneath of the head band to stop them sliding down.

[cava]

I have used them without the shield and I gaffer taped a small piece of foam to the underneath of the head band to stop them sliding down.

That just may work! Thanks Bob.