A Word About Hearing Protection....

[SittingElf]

Greetings,

I am starting to see more and more reviews online regarding tools and machines that have been designed to reduce noise levels. A lot of the reviewers are saying things like "so quiet, I don't even need hearing protectors" or similar statements. This is a false premise, and one that if followed can cause long term, permanent hearing loss...and here's why....

While an indvidual machine may actually have a decibel level low enough that damage to hearing may not be a factor, it is the compounding effect of multiple machines, or wood being cut, planed, jointed or otherwise manipulated that increases the overall noise level.

When considering the typical woodshop, there will normally be a Dust Collector in operation with machines and tools that create sawdust. Additionally, there may be an Air Filtration system operating, and potentially an air compressor as well as other noisemakers.  The compounding effect of all of these machines in operation can have very detrimental effects on your hearing.

To understand how hearing is damaged, you have to look at what part of your ear is affected. The primary receptors are called Cilia, which are hair-like follicles.  Think of your grass lawn. If you walk occasionally on your lawn, the grass is compressed, but will spring back up in a few minutes to a normal upright position. However, if you constantly walk or step on the same patch of lawn, eventually you will wear away the ability for the grass to recover...and often you'll be left with a brown spot where grass used to grow.  Cilia in your ear acts EXACTLY the same way. The occasional exposure to high decibels will knock the cilia down, but they will recover and no hearing loss occurs. BUT... if you constantly expose those same cilia to high decibels, they get to the point where they WON'T recover, and you lose the ability to hear in the frequency levels that have been affected...and that is now permanent because you can't plant any new seeds.

In general terms, hearing protection should be worn for all noise levels above 80dB as a safety precaution. Regular exposure to noise levels above 85dB can begin to become dangerous, especially for extended exposure. Above 90-95dB, you enter a severely dangerous zone of noise, some of which can cause permanent hearing loss VERY quickly.

Why take a chance?  If you have to talk above a normal speaking voice to be understood by someone within 5 ft of you, you NEED to be wearing protection!!  Please protect your hearing! Ignore the reviewers who say they "don't" need to use them... they won't be able to hear you in the future! Be smart, and have a spare set or two in your shop for when people are visiting while you work, and MAKE them wear them.

I am a helicopter pilot, and very cognizant of the dangers of hearing loss. Many of my colleagues have diminished hearing in some frequencies due to the wear of substandard headsets while flying. Fortunately, one of my extra duties while I was an Army Officer was to be my Division's Hearing Conservation Officer, and I went to school to become a Certified Hearing Conservationist Expert, so I speak from academic knowledge, not from my back end... and hope that my fellow woodworkers will pay heed.  You really don't want to live a life where your most used phrase is "What did you say...."

Take it or leave it... just hoping that some of you will "listen"....  [wink]

Cheers,

Frank

 

[greg mann]

Good post, Frank. After 47 years in a metalworking environment, most of which was spent with no hearing protection, I can testify. My late wife was a gerontologist and was used to raising her voice to be heard so she was sympathetic to my hearing loss, and she had a fairly deep voice for a woman. My new bride has a voice with a different pitch, has worked in a hospital setting her entire life, so she speaks softly, and will not raise her voice on the request for a repeat. She also likes to be answered promptly which doesn't give me time to decipher and fill in the words I missed.  [unsure] (Other than this one characteristic she is wonderful.)  [wink]

I suspect a hearing aid is not far off.

 

[ElCabong]

Thank you for the valuable information. Safety is always a concern of my mine. I am curious of your opinion on ear protection. Recommendations include using over-the-ear (muffs) or soft foam ear plugs. What about the Bose-type noise canceling head-sets? Are they better or worse than the previously aforementioned standard products?

 

[Greg M]

Thank you for taking the time to post this.  I would ask you to go one step further and tell us what we should be looking for in hearing protection.  What makes one piece of hearing protection better then another?  What type of hearing protection is sufficient for woodworking? 

Would something like a set of bluetooth noise canceling headphones be sufficient?  If I'm going to start using hearing protection more often I would like to hear some music sometimes.

 

[Greg M]

I see someone beat me to the punch

 

[dltflt]

Thank You Frank for all of my the valuable information.

 

[Sparktrician]

Frank,
    You might want to address the two types of sound transmission from the academic viewpoint.  As a long-time shooter, I'm quite aware of these from the end-user standpoint, so I wear both innies (plugs) and outies (muffs) when I shoot.  Innies and outies are also mandatory when I use the planer.  Otherwise, I use outies in the shop.  Mine are rated to 31 dB of reduction.  I'm already 100% deaf in one ear for other reasons, so preservation of the other ear's usefulness is not an option. 

 

[WarnerConstCo.]

I don't know, not being able to hear what the old lady is complaining about might be pretty handy. 

 

[SittingElf]

First, let me address the various forms of hearing protection.

The absolute BEST is what Sparktrician mentioned. Specifically wearing BOTH "innies" and "outies". As a matter of fact, that is what I use when flying. It's maximum protection against both steady-state high decibel noise, AND against instant percussive noise (like a gunshot). The percussive noise is, again to use a parallel, like stomping on the grass with your heel, which causes much more long-term damage than simply walking across the grass. (The military DEMANDS that artillery soldiers, tankers, and others in high noise environments wear both...and they have stopped allowing disability status for those who they have determined to have hearing loss due to not abiding by using appropriate protection)

As for noise-reduction headsets...yes they do reduce damage because they "counter" steady state sound by matching the frequency noise with an exact opposite, thereby cancelling out. The problem is that they only really work well for true steady state noise. They are much less effective against percussive, or instantaneous sounds like a hammer blow, or power nailing.

There is nothing wrong with quality bluetooth headsets, and when I say quality, I mean that the outer muffs need to attenuate the decibel level below the danger threshold. Most hearing protectors will state the decibel reduction that their products are certified for, but I'd still take those numbers with a grain of salt. If the aids don't fit well around your ears and make a tight connection, they will "leak" sound, and that's why using double protection (innies and outies) is the MOST effective method of hearing protection.

Listening to music or radio, or whatever through a quality set of bluetooth, or powered hearing protectors is fine...UNLESS you have the volume for said music set to a level which also exceeds the danger margin of measurable decibels.

Summary:
BEST: Inner plugs worn with a quality outer hearing protection headset
GOOD: Either inner or outer protectors that are rated for a minimum of 20 Decibel sound reduction. The more the better.
OK: Powered noise reduction headsets, and or bluetooth headsets as long as they are also rated for decibel reduction.
AVG Minus: Cheap ballistic headsets made for casual shooting. Protect against percussive damage but less than effective against steady-state high decibel noise
BAD: Cigarette filters, cotton balls, Chewing gum (yes I've seen it), or similar expedients.
UNACCEPTABLE: No hearing protection at all. "Can you hear me??"  I said "CAN YOU HEAR ME!!!???"

Cheers, [big grin]

Frank

 

[SittingElf]

Oh... as Steve Jobs used to say... "There's one more thing..." [smile]

If you own a smartphone like iPhone, Android etc., there are a number of decibel meter apps available, some of which are really excellent and accurate. If you don't know what the noise level is in your shop close to your machines, these are very worthwhile apps that are inexpensive and informative.

I tested the one I have on my iPhone against a dedicated decibel meter. It came within 1 decibel up or down on virtually all of my tests. Excellent tool to have!

Cheers,

Frank

 

[MrGinCT]

As was said earlier, look at the NRR number when you are considering a set of hearing protectors.  I wouldn't buy anything with less than a NRR of 29.  I have hearing loss in both ears and wear hearing aids to compensate. 

You can never recover hearing loss regardless of what type of hearing aids you wear, so take every precaution NOW.

Make sure that whatever type of hearing protection that you buy, that it fits you properly and that you ALWAYS wear it, even if you are only going to be running your equipment or power tools for just a "minute".

 

[greg mann]

I don't know, not being able to hear what the old lady is complaining about might be pretty handy.

Only in the short term, Darcy.

 

[Sparktrician]

There are two ways that sound gets into your head.  The first is via direct pressure on the eardrum.  This is resolved by high-quality ear plugs (innies) like the Howard Leight Laser Earplugs which have a noise reduction rating (NRR) of 32 dB.  There's another model, the Max 1 with an NRR of 33.  The second way sound gets in is via bone conduction.  Ear muffs attenuate the bone conduction of sound to the brain.  A search on Amazon reveals a number of options with an NRR of 31 or better.  I know that when I was in the Navy (back in the days of iron men and wooden ships), we were working in a fully enclosed generator compartment with three huge GM V-8 diesels whose pistons measured over 12" across, plus three more gennies of smaller sizes, and the Navy refused to provide any hearing protection whatsoever.  When we got off watch in the G-Room, it was 12 hours or more before we could really hear what other crewmen were saying.  Better to protect what you have while it still works. 

 

[Dan Clark]

+1 on all of the above.  Unfortunately, I speak from experience...

I have a 70% hearing loss in both ears.  I wear digital hearing aids.    The good news?  With the hearing aids, my hearing is quite good.

The bad news?  Good hearing aids work well and not so good in others.  In a noisy room with a hard ceiling, it's still a problem because the microphones point up.  Lots of muddied sound everywhere. And you can't get them wet.  And you have to change batteries every three days. And you have to stick them in a dryer every night.  And then there is the cost - $6,000 for the pair. I happily forked over the money to get decent hearing, but it still stung.

Now let's talk about the subtle effects of hearing loss.  Most people think that hearing loss is just missing some or all the words spoken.  That's true, but it's the subtle effects that are the major problem.

With partial (not total) hearing loss, what really happens much of the time is that the person CAN hear the words, but they can't quite understand them.  So their brain has to decipher the word based on partial information.  That takes time and a lot of concentration effort. 

For many of us, listening is (was) an exhausting effort.  And the processing delay means you're always trying to catch up to the conversation.    For example, Joe says, "This is a rail saw.  You use it with a guide rail."  Bob (the partially deaf fellow) hears, "This is ra*8 szz. You ***** with ****** ****. "  While Joe has moved on to describing a router, Bob is trying to decipher the first two sentences.  He takes an additional 1/4 to 1/2 second to understand the first sentence, and misses part of second sentence.  And Bob has to race to catch up to the next part of the conversation.  Over and over and over and...

So Bob doesn't quite get all of the information.  He's tired from the effort of listening.  He's more likely to shy away taking part in discussions.  And more likely to watch a video demonstration (with replay), or read an article or a book on the subject.  And unfortunately, he may be perceived as being a bit "slow" or being an introvert.

Sounds like fun, doesn't it?  Well that was me until I got hearing aids a few years ago.  It affected my relationships and my work. 

My message: PROTECT YOUR HEARING!

/soapbox = off.

Regards,

Dan.

 

[leer]

Frank,

Thanks for posting the detailed information.  I'll have to try wearing both "innies" and "outties" --not only for woodworking, but at the shooting range.  A bit surprised that I have never considered using both. 

I went to an indoor range last year with a son-in-law and nephew, and was amazed at how my ears rang after we left.  Seems like everyone was shooting AR-15s, and we were in the minority, mostly shooting handguns. I am certain that since we were indoors and in much closer proximity to other shooters, it made a huge difference.  I've never experienced that kind of ringing from shooting my own AR-15 at an outdoor range.

 

[Greg M]

Oh... as Steve Jobs used to say... "There's one more thing..." [smile]

If you own a smartphone like iPhone, Android etc., there are a number of decibel meter apps available, some of which are really excellent and accurate. If you don't know what the noise level is in your shop close to your machines, these are very worthwhile apps that are inexpensive and informative.

I tested the one I have on my iPhone against a dedicated decibel meter. It came within 1 decibel up or down on virtually all of my tests. Excellent tool to have!

Cheers,

Frank

Which app?

 

[Dan Clark]

Oh... as Steve Jobs used to say... "There's one more thing..." [smile]

If you own a smartphone like iPhone, Android etc., there are a number of decibel meter apps available, some of which are really excellent and accurate. If you don't know what the noise level is in your shop close to your machines, these are very worthwhile apps that are inexpensive and informative.

I tested the one I have on my iPhone against a dedicated decibel meter. It came within 1 decibel up or down on virtually all of my tests. Excellent tool to have!

Cheers,

Frank

Which app?

On the iPhone, try FFT Plot or Decibel Meter Pro.

Dan.

 

[Sparktrician]

I use deciBel Pro on the Android. 

 

[grbmds]

I have used the foam earplugs with the brand name "Sparkplugs". They are avery effective in noise suppression; a stated 29 decibels of NR. I don't know if they really reach their stated NR. However, with them in, I can mow on my lawn mower and work in my shop and the noise is suppressed sufficiently that I can barely hear my dust collector, saws, routers, whatever. I can't hear much of anything else either which is the problem I have with the foam inserts. I also understand that some people find those very uncomfortable but, for those who can wear them and don't mind not hearing anything else either,  I believe they are effective.

What I'm looking for is effective NR and the capability to hear music via Bluetooth at the same time. I have seen Peter Parfitt's review the the muffs with BT and may have to try those, but other products I've tried either have poor BT connection or don't suppress the sound enough.

 

[BMAC]

Very important safety considerations raised hear (pun intended)! Once you've damaged your hearing it doesn't get any better. I protect my hearing, eyes, body, etc at all cost. A buddy has tinnitus and he hears a hi-pitched whine in his ears 24/7 and has to take medication to sleep as the noise is ever present.

I wear my electronic hearing protection and eye protection for all equipment use, including the paslode, saws, jigsaw, you name it. You can still hear even quiet speaking voices but the high damaging noises are totally eliminated. One side benefit is that homeowners who like to stand over you and chat non-stop to me while I try to work don't tend to do that if you're sporting the muffs (time is money to me).

I have Dillion's and they have excellent sound quality and are a small format set so they won't get in your way. Also, I shoot competitively (IPSC.org or USPSA for those in the USA) and double plug which is moulded ear plugs first and the electronic earmuffs and I've worn the muffs for 8-10 hours at matches with no discomfort.

Plugs, regular muffs or electronics, it doesn't really matter which as long as you use something as each and every excessive sound has an cumulative effect.