Ear Defenders

[Thomas Hayman]

I wear my Peltors at work (large printing firm) and they cut out so much yet still allow me to hear people shouting at me. Definitely recommend and really not expensive when you think about it.

 

[Grahamshed]

I just use some cheapo ones from the local hardware store but would like to get some better ones so all the above is going to prove very useful.

regards

Brian

SAME HERE, AND EVEN THEN I HAVE TO ADMIT I DON'T WEAR THEM VERY OFTEN. MOST OF MY MACHINES ARE ONLY WORKING FOR A FEW SECONDS AT A TIME AND I FORGET.

( I ASSUME IT'S OK TO SHOUT ON THIS THREAD ? )

 

[Racers]

Pardon?

Pete

 

[brianhabby]

I just use some cheapo ones from the local hardware store but would like to get some better ones so all the above is going to prove very useful.

regards

Brian

SAME HERE, AND EVEN THEN I HAVE TO ADMIT I DON'T WEAR THEM VERY OFTEN. MOST OF MY MACHINES ARE ONLY WORKING FOR A FEW SECONDS AT A TIME AND I FORGET.

( I ASSUME IT'S OK TO SHOUT ON THIS THREAD ? )

It's okay, I've got my (cheapo) ear defenders on

regards

Brian

 

[Jelly]

I'd vote for peltor's too, far and away the most comfortable ear defenders out there. The Optime 3 might be a bit overkill depending on what you're doing, they're designed to suppress bass frequency noises better.

I was thankful of them when I worked in a sawmill, but having taken them with me to a rather less noisy joinery factory (where the noise can be heard, but not felt or seen ) they seem to suppress a lot of non-shouted comunication too; most of the other staff have been issued the "normal" optime's.

Arco have a massive range, do mail order and have a good branch network; they're always my first port of call for PPE. The optime's are about £11 there.

 

[Eric The Viking]

I'd vote for peltor's too, far and away the most comfortable ear defenders out there. The Optime 3 might be a bit overkill depending on what you're doing, they're designed to suppress bass frequency noises better.

I was thankful of them when I worked in a sawmill, but having taken them with me to a rather less noisy joinery factory (where the noise can be heard, but not felt or seen ) they seem to suppress a lot of non-shouted comunication too; most of the other staff have been issued the "normal" optime's.

They shouldn't really do that (suppress speech, I mean). They drop sound levels overall, but the ear, which has a sort of 'automatic volume' mechanism compensates for that -- unless there's already damage. The thing is though that speech is directly competing with the smaller machines, so if there are proportionately more of them, making out speech will be harder.

My mum lived and worked around our family's sawmill through her teens and early twenties. She didn't work on the machines but she did help in the office, and often had to go out into the mill proper running errands.

We're having the Dickens of a job persuading her to get a proper hearing aid now (at the ripe old age of 85), but there's no doubt she's got a really bad notch at around 3-6kHz. That's just the frequencies damaged most by planers and big saws (of which there were plenty). I can't prove it, obviously, but I have very strong suspicions that's the origin of the problem. Her mum went profoundly deaf in her 80s (grandpa ran the felling gang and the big bandsaw), and again, I think that's because of incidental noise exposure in the 1930s onwards. Nobody wore hearing protection, but they knew it did damage - as a kid I was always sent packing whenever they used the Wadkin pull-over crosscut (it was on its own in the shed they kept hardwoods in), as that made a heck of a noise for its size.

It's the higher pitched sounds, on balance, that the ear is most vulnerable to. I think it's because low-pitched, loud sounds do occur in nature (waterfalls, thunder, etc.), whereas high-pitched ones don't, and anyway, by definition, a low sound has a slower change in pressure acting on the ear, so less percussive effect (the ear is, after all a bio-mechanical device that's shaken in operation).

You 'feel' low sounds rather than hear them. 20Hz is generally considered to be the lower limit of human hearing. Below that you can make out individual vibrations, so the brain doesn't interpret it as 'sound', but you tend to feel, usually in the chest cavity loud sounds from about 35Hz downwards.

IIRC, the bottom E on a standard bass guitar is usually around 32Hz.

Those frequencies between around 800Hz and 3.5kHz are by far the most important, as that's the range most useful for human speech. I don't know how true it is, but when the telephone network first had the opportunity of using better microphones, and putting several calls down one wire simultaneously (multiplexing), and when "talkies" were being standardized in the movie industry round the late 1920s, discussions started about how much bandwidth was needed for clear speech.

Experiments showed up to 2.5kHz was about the minimum needed for intelligibility, which is what became standard for telephones (to this day), and the "Academy curve" in the movies went up to an outrageous 7kHz. Luxury HiFi!

It's a very odd curve though - not linear at all, and although the Academy claimed it was to optimise the intelligibility of dialogue in big cinemas, it's more likely to have been an attempt to compensate for the horrible horn loudspeakers popular in cinemas until the 1970s (they're very efficient, but hi-fi they ain't!).

FWIW, I *think* the BBC's long wave transmitter at Droitwich, currently used for Radio 4, Cricket, etc. used to be limited to 7kHz (the channel spacing is now only 9kHz so it certainly can't be any more than that, and is probably less). I can't find the spec anywhere (haven't Googled lots - don't have time), but it's the lowest-fi of any of the BBC's output (apart from DAB, grrrr).

Sorry - huge ramble. Must get back to work

E.

 

[Lord Kitchener]

Not too many music fans here then, or maybe not everybody is faced with having to wear ear defenders for most of the day? I think I am the only poster who has mentioned noise cancelling earphones so far. BTW, they can be bought on their own, for use with any Walkman type unit and they really make a difference.

 

[Eric The Viking]

I'm a music fan!

And that's one reason why I'm careful: I just don't trust the technology behind "noise cancelling" to protect my hearing sufficiently. As applied to ear defenders, that is - it does work quite well in other applications.

I'm getting used to trusting my auto-darkening welding helmet though , so maybe I ought to relax a bit. Trouble is, once it's damaged, hearing or eyesight, it's permanent.

Perhaps I'll stay cautious.

E.

 

[Lord Kitchener]

And that's one reason why I'm careful: I just don't trust the technology behind "noise cancelling" to protect my hearing sufficiently. As applied to ear defenders, that is - it does work quite well in other applications.

It's not just the noise cancelling, that's just the icing on the cake. The cake is provided by the earplugs themselves, which stop a good deal of the noise on their own. I shouldn't think anyone is fussier about their hearing (or my other faculties) than I am. When friends visit my workshop they are amused at the amount of stuff I have to remove before I can talk to them, whereas I am horrified when I see how careless they are, for instance operating concrete disc cutters with no protective gear whatever!

 

[Jelly]

I'd vote for peltor's too, far and away the most comfortable ear defenders out there. The Optime 3 might be a bit overkill depending on what you're doing, they're designed to suppress bass frequency noises better.

I was thankful of them when I worked in a sawmill, but having taken them with me to a rather less noisy joinery factory (where the noise can be heard, but not felt or seen ) they seem to suppress a lot of non-shouted comunication too; most of the other staff have been issued the "normal" optime's.

They shouldn't really do that (suppress speech, I mean). They drop sound levels overall, but the ear, which has a sort of 'automatic volume' mechanism compensates for that -- unless there's already damage. The thing is though that speech is directly competing with the smaller machines, so if there are proportionately more of them, making out speech will be harder

Its not that it suppresses speech outright, so much as requires you to actively focus on listening as the 3 offers extremely high (36dB) attenuation across the whole frequency spectrum (unlike most hearing protection which focuses on attenuating the more damaging high frequencies)... Certainly the background noise has an effect too.

Teniously related; I miss the old Waco's (22B or C?) sound, as it spun up its cutters it reminded me remarkably of the opening notes of Gershwin's Rhapsody in Blue, it was a cheery way to start a shift.

Also they cost nigh on a tenner more, so if you dont need that level of protection (and your employer isnt paying) its a waste of money.

Not too many music fans here then, or maybe not everybody is faced with having to wear ear defenders for most of the day? I think I am the only poster who has mentioned noise cancelling earphones so far. BTW, they can be bought on their own, for use with any Walkman type unit and they really make a difference.

Ear defenders are designed, tested and certified as fit for purpose... Noise canceling headphones are not; for me its that simple. Incidentally, I could put small earbud headphones on under my "cans" if I wanted, but i'm a firm beliver that effective communication and situational/environmental awareness are the most important aspects of safe machining practices.

My perceptions are definatly coloured by having worked in an extremely high noise environment... With *peak* noise levels inside some of the soundbooths/sawcabs approaching the threshold of pain, you don't take chances... The working practices stick, even when the risk is lower.

 

[Eric The Viking]

Very sensible indeed.

The only thing I would say about "too much" protection is that it isn't a waste. The scientific evidence is that damage is from cumulative exposure (a function of loudness X time exposed). The more you attenuate loud sounds the less damage you'll do to your hearing, so all protection is good and you can't have too much - from the point of view of saving your ears. The official numbers expect you to have hearing loss in old age because of environmental exposure, although research proves it isn't a always natural effect of ageing, but based on the human environment mainly.