Is ANR enough to properly protect your hearing?

O

OverTQ

Pre-takeoff checklist
Joined
Dec 25, 2014
Messages
146
Display Name
Display name:
OverTQ
I'm doing a little research on headsets.

What I've gathered so far is that ANR can respond well enough to lower frequencies to adequately protect hearing damage from those frequencies. High frequencies, such as those from turbine engine noise, can not be addressed by the ANR and must be silenced passively.

So, I have a few questions.

Is my summary above accurate?

Do modern ANR headsets (like those from Bose, Lightspeed, DC, and Sennheiser) address this with an adequate level of passive protection?

Should a pilot consider the type of aircraft they fly when choosing to use ANR? (For instance, it might be fine for someone flying a 172 but shouldn't be used by someone flying a turbine helicopter.)

Are there any other other legitimate safety concerns with ANR?

Is anyone aware of any studies that have looked into this?
 
10 years ago when I was seeing an audiologist and ENT regularly to deal with tinnitus i did my own research. At that time the medical professionals I spoke with weren't convinced that ANR was beneficial for hearing protection. To my knowledge nothing has changed but it's been a year or two since I've had any discussions about it with those professionals. Here are a couple of articles that my audiologist sent me. In her opinion passive still rules. Adding ANR may improve audio quality and comfort but not protection. The headsets that have ports in the cups (Bose) to allow noise in (to excite their ANR) are the worst at passive protection. As you've noted, the ANR only deals with low frequencies so the open holes are letting high frequency noise in unabated. The thing that drove me to ask about ANR was that I noticed the ringing in my ears was worse after flights with ANR headsets. That was counter-intuitive. All that said, I still use a Gallet helmet with mil spec ANR in Cubs and Lightspeed Zulu 2s in the Cessna. Previous to that I used Sennheisers and DC ANR sets, which were also good at passive attenuation. The trend towards smaller and lighter isn't necessarily healthy.

These articles aren't new but they're good reading.

http://aearo.com/pdf/hearingcons/anr.pdf

http://www.caohc.org/updatearticles/fall03.pdf
 
Last edited:
ANR is mostly done for audio quality rather than hearing protection. Not saying an ANR headset can't also provide good hearing protection, but the hearing protection comes primarily from physically blocking the sound waves (aka passive protection).
 
I am devoted to my QT Halos, which offer (to me) at least as good an experience in noise reduction as ANRs, and it's passive, which means the noise is actually attenuated and thus, not harming your hearing.

In addition, they are so light, they almost disappear.
 
rocketflyer84 said:
ANR is mostly done for audio quality rather than hearing protection.
Click to expand...

That is correct because with ANR you ear is still hearing...essentially you are just hearing the sound AND the inverse of that sound which cancel each other out to your ear drum. Your ear drum is still getting the sound pressure wave...plus the inverse sound wave

That is why I HATE ANR for anything other than my aviation headsets. I l feel like I should be hearing something cuz I can sense the pressure but my brain is freaked out because there is no audible sound to decode. At least in the plane there is still background noise that is making it through to actually hear.

But the first objective to a good ANR headset is to passively reduce the sound levels inside the ear muffs so that the ANR has less work to do...hence some degree of hearing protection.
 
Last edited:
SCCutler said:
I am devoted to my QT Halos, which offer (to me) at least as good an experience in noise reduction as ANRs, and it's passive, which means the noise is actually attenuated and thus, not harming your hearing.

In addition, they are so light, they almost disappear.
Click to expand...

The worst part is remembering to change the ear plugs every once in a while. My right ear was ringing after a flight last night, so I'm thinking it's finally time to change it. I did expect it to last longer, though. Granted, my audio was up a bit louder than usual, too... so I may try to tone it down next time before replacing them.
 
Shawn said:
Your ear drum is still getting the sound pressure wave...plus the inverse sound wave
Click to expand...

This isn't correct. The pressure wave is the sound. It's cancelling out both.
 
In my experience on noise reduction, sound quality and comfort headsets are ranked as:

In-ear type > over-ear ANR > over-ear sans ANR

Having tried various types I find that in-ear tends to be quieter even though it lacks ANR and it's most certainly much more comfortable for long trips.
 
OverTQ said:
This isn't correct. The pressure wave is the sound. It's cancelling out both.
Click to expand...


Yes...not correct terminology, but the wave (plus inverse) is still hitting your ear drum. ANR does not stop the wave...that would be passive reduction. It cancels them out acoustically but not physically.
 
"Acoustically" and "physically" are the same thing. When it comes to the physics (and acoustics and hearing loss risk) the only thing that impacts on the eardrum is an oscillating air pressure wave (which we perceive as sound). Cancel it out with the reciprocal pressure wave and there is less sound pressure (sound intensity) delivered to the eardrum. That is all that matters when it comes to hearing loss.
 
Last edited:
The only way to answer the question is to measure the sound intensity (sound pressure) on the appropriate scale (dBA) inside the ear cup of an ANR headset and and inside the ear cup of a passive headset in the same noise environment. I'm betting that the measured sound pressure is lower inside the ANR. Lower sound pressure = lower risk of hearing loss.
 
I read a study once that claimed that in ear foam earplugs did not help to protect from very low frequency sound that is damaging to hearing, sounds below the threshold of our hearing and recommended over the ear style hearing protection. This was a weapons firing based study. I assume it translates over to aircraft.

I personally use A20's to fly and Peltors to shoot. I do have more sensitive ears though so I'm a bit more conscious to sound db. I also have some Bose qc15's and they do a fairly good job at making airline travel not so noisy.

Over the ear like the qc2(?) seemed pretty worthless to me.

Sent from my iPhone using Tapatalk
 
All I know is that I used PNR headsets (think green and expensive) in my C-206, 207 days. After 7 or 8 hour flying days I would have a massive headache and just be absolutely worn out. When I got my first ANR headset, no more headaches and I felt a lot better at the end of the day.
 
27 total years of (3 medic + 24 pilot) flying...23 with PNR headsets, the last 4 with ANR, and as of my June audiogram, not significant hearing loss at age 53. Anything that attenuates the decibel levels to less than 75 db makes it extremely unlikely that noise-related hearing loss will occur, so any headset that will do that is adequately protective. The ANR is nice because in reduces the drone, enhances audio and frankly, seems less tiring.

http://www.nidcd.nih.gov/health/hearing/pages/noise.aspx

Here's a good basic primer of noise-related hearing loss from the NIH.
 
Shawn said:
Yes...not correct terminology, but the wave (plus inverse) is still hitting your ear drum. ANR does not stop the wave...that would be passive reduction. It cancels them out acoustically but not physically.
Click to expand...

No it's not hitting your ear drum. The ANR "pushes back" so it "stops" the wave. The end result is static, not dynamic pressure, so it doesn't move your eardrum, so it won't stress anything, so it won't damage your hearing. It's like going snorkeling, there is higher static pressure outside your ear, but no dynamic pressure, so it won't damage your hearing.
 
so sound energy enters the ear cup and an opposite phase sound wave is created to cancel it. I understand that science but where I get lost is that we know that energy is not terminated, it's doubled. We know Einstein said that energy cannot be created or destroyed, it can only be changed from one form to another. What happens to the doubled sound energy and how does it affect hearing in the long term?
 
Shawn said:
Yes...not correct terminology, but the wave (plus inverse) is still hitting your ear drum. ANR does not stop the wave...that would be passive reduction. It cancels them out acoustically but not physically.
Click to expand...

Acoustically is physically, by introducing the inverse wave form, the set of waveforms nullify before hitting the tympanic membrane. It doesn't "trick the mind" it stops the air pressure before it gets to your ear drum.
 
My parents are both losing their hearing, it really sucks for all parties. I just bought some new 33NRR plugs to use while riding the motorcycle and for mowing, etc... Motorcycle is really bad, but ANR in the plane seems to do the trick. I grew up on a farm, so probably did some damage back then with farm equipment and guns, I've noticed my hearing isn't what it used to be and I'm still fairly young, so I don't take any chances anymore.
 
What I'm hearing is doubling up may be worthwhile... perhaps my Halos in the ear with some Bose non-aviation ANR headphones over top.
 
Challenged said:
My parents are both losing their hearing, it really sucks for all parties. I just bought some new 33NRR plugs to use while riding the motorcycle and for mowing, etc... Motorcycle is really bad, but ANR in the plane seems to do the trick. I grew up on a farm, so probably did some damage back then with farm equipment and guns, I've noticed my hearing isn't what it used to be and I'm still fairly young, so I don't take any chances anymore.
Click to expand...

My great uncle flew in WWII then started a seaplane service after the war. When I told him I was starting flying his first words to me were, "That's great, buy the best pair of headsets you can and always wear them." He's deaf as a post and even with his hearing aids in, a conversation with him will leave you hoarse from shouting.:(
 
mkosmo said:
What I'm hearing is doubling up may be worthwhile... perhaps my Halos in the ear with some Bose non-aviation ANR headphones over top.
Click to expand...

I don't think "doubling up" is necessary unless you're in a really loud plane all day every day. Good 'in ear' sets do an excellent job. I end up in the hearing box every year or two, and in 30 years my test results haven't changed much and I work in some much louder environments than airplanes; never have I 'doubled up' on hearing protection, but I do use whatever I am using religiously, be it it over the ear cups or ear plugs. I have a Clarity Aloft set and find them just as functional as my Zulus.
 
....WHAT?!
lol


Over 4k hrs in everything from 200series cessnas, to rag wing taildraggers, to radials, seaplanes, to turbines, nearly all those hours with ANR and my hearing is still fine.
 
Henning said:
I don't think "doubling up" is necessary unless you're in a really loud plane all day every day. Good 'in ear' sets do an excellent job. I end up in the hearing box every year or two, and in 30 years my test results haven't changed much and I work in some much louder environments than airplanes; never have I 'doubled up' on hearing protection, but I do use whatever I am using religiously, be it it over the ear cups or ear plugs. I have a Clarity Aloft set and find them just as functional as my Zulus.
Click to expand...

I was being a little facetious just for the sake of being a PITA. :yes:

Before the CA and Zulus, what's your headset history looked like? I'm curious for both aviation and non. I'm still young, but in the louder environments (some significantly more so than aviation), I've just used plain foam plugs and been fine.

With regards to the airplanes, though, some of the folks around that have been flying 30+ years and have seen the evolution of the headset from something with the effectiveness of none through the modern Halo and Zulu are an interesting study. Some with amazing hearing and some with significant loss. The chief instructor at the airport I'm based out of has significant loss (at 90 years old) and still only grabs a pair of cheapo ASAs when he needs a headset...

DCs or Halos, I still get some mild ringing after a longer flight, but I don't anymore notice any fatigue at ~3 hours like I did with DCs.
 
mkosmo said:
With regards to the airplanes, though, some of the folks around that have been flying 30+ years and have seen the evolution of the headset from something with the effectiveness of none through the modern Halo and Zulu are an interesting study. Some with amazing hearing and some with significant loss. The chief instructor at the airport I'm based out of has significant loss (at 90 years old) and still only grabs a pair of cheapo ASAs when he needs a headset...
Click to expand...
I guess that would be me. Other than a few hours when I've been in someone else's airplane using their headset I have never flown with ANR. On the other hand I have always used in-ear protection. In the early days with no intercom or headset I wore foam earplugs. Later I used foam earplugs under non-ANR DCs. Now I use a Clarity Aloft in-ear headset. I'm guessing that I have about 6,000 hours in piston airplanes. The last time I had my hearing tested was a couple years ago and the ENT said that my hearing was better than average for my age (mid-50s at the time). Some loss in the high frequencies but not as bad as most. He was comparing me to the general population, not just pilots, since I'm not even sure he knew I was a pilot.

Note: I am in no way implying that ANR is not beneficial, just that I never owned an ANR headset or used one on a regular basis.
 
Last edited:
Stewartb said:
so sound energy enters the ear cup and an opposite phase sound wave is created to cancel it. I understand that science but where I get lost is that we know that energy is not terminated, it's doubled. We know Einstein said that energy cannot be created or destroyed, it can only be changed from one form to another. What happens to the doubled sound energy and how does it affect hearing in the long term?
Click to expand...

No. The energy isn't doubled.

What's the energy of a 0 Hz signal?
 
mkosmo said:
I was being a little facetious just for the sake of being a PITA. :yes:

Before the CA and Zulus, what's your headset history looked like? I'm curious for both aviation and non. I'm still young, but in the louder environments (some significantly more so than aviation), I've just used plain foam plugs and been fine.

With regards to the airplanes, though, some of the folks around that have been flying 30+ years and have seen the evolution of the headset from something with the effectiveness of none through the modern Halo and Zulu are an interesting study. Some with amazing hearing and some with significant loss. The chief instructor at the airport I'm based out of has significant loss (at 90 years old) and still only grabs a pair of cheapo ASAs when he needs a headset...

DCs or Halos, I still get some mild ringing after a longer flight, but I don't anymore notice any fatigue at ~3 hours like I did with DCs.
Click to expand...

I started in the early 90s with a cheap pair of Soft Comms and switched to a set of Peltors when I bought my Travelair and used the SCs as a passenger set. The Peltors (passive) were great and as comfortable as any ANR set today. I can't wear DCs for more than about 15 minutes. You don't need to eliminate all the noise to prevent hearing damage.

For non aviation, 3M foam plugs that are sitting around the shops in big boxes, or a set of passive ear cups that are typically hanging around the entrance to engine rooms, again, the Peltors are typically the most comfortable and quiet.
 
Last edited:
I've heard that argument before. Just not from anyone in science or medical professions. My doctors still won't say that ANR is beneficial for hearing protection. It has benefits but alone it isn't enough. Why is that if 0hz is true? I told my wife that I was going to put her Zulus on the dog when I fly today just to see how the dog responds. Her hearing is far more acute than ours.

So a sound wave enters an ear cup at approx 768mph and in the space of a millimeter or two a microphone hears the sound, processes the frequency, and signals a speaker to create an opposite sound wave? Is it perfectly phased or is it just good enough that a human ear recognizes a reduction of noise? I use Zulu 2s and find them superior to the Sennheisers they replaced for noise attenuation, but I still get increased ear ringing after a flight. In fact the ear ringing, while difficult to quantify, is about the same with old DC 13.4 passive sets as the Zulus. I prefer the Zulus but I can't testify that they're better hearing protection. I can make the argument using the ANR marketing claims but that doesn't prove up in my own ears.

It's an interesting topic no matter how often it comes up.
 
Last edited:
I got my PPL in 1989 using the hand mic and the cabin speaker in a Cessna 152. After a couple years I started using a cheap Soft Com headset and discovered why ATC communication was my weakest subject in flight training.
 
Stewartb said:
I've heard that argument before. Just not from anyone in science or medical professions. My doctors still won't say that ANR is beneficial for hearing protection. It has benefits but alone it isn't enough. Why is that if 0hz is true? I told my wife that I was going to put her Zulus on the dog when I fly today just to see how the dog responds. Her hearing is far more acute than ours.

So a sound wave enters an ear cup at approx 768mph and in the space of a millimeter or two a microphone hears the sound, processes the frequency, and signals a speaker to create an opposite sound wave? Is it perfectly phased or is it just good enough that a human ear recognizes a reduction of noise? I use Zulu 2s and find them superior to the Sennheisers they replaced for noise attenuation, but I still get increased ear ringing after a flight. In fact the ear ringing, while difficult to quantify, is about the same with old DC 13.4 passive sets as the Zulus. I prefer the Zulus but I can't testify that they're better hearing protection. I can make the argument using the ANR marketing claims but that doesn't prove up in my own ears.

It's an interesting topic no matter how often it comes up.
Click to expand...

Yeah, I doubt any doctor who isn't doing the research will say anything. Malpractice is scary noawadays.

But I'm glad I'm not the only one who still gets ringing with noted decreases in sound level (even though my case is PNR-PNR. How long until an audiologist publishes a whitepaper on this? Until then, I guess I'm going to be biased and stay with the Halo since he's an audiologist.
 
For as long as I've known my brother in law, probably the most active and calculating pilot I know, he's used foam ear plugs under his headsets. That was true before ANR and remains true with ANR. I suspect any medical professional would endorse that habit. Funny thing, I find it too quiet. Similar to my first flight with the Zulu 2s. Lack of sound, or a significant change in normal sound levels, is distracting to me. I've never used foamies under my headsets long enough to get used to it.
 
Stewartb said:
For as long as I've known my brother in law, probably the most active and calculating pilot I know, he's used foam ear plugs under his headsets. That was true before ANR and remains true with ANR. I suspect any medical professional would endorse that habit. Funny thing, I find it too quiet. Similar to my first flight with the Zulu 2s. Lack of sound, or a significant change in normal sound levels, is distracting to me. I've never used foamies under my headsets long enough to get used to it.
Click to expand...

I tried the double up a couple of times before, and in typical planes, I find it too quiet as well. There are nuance sounds of the engine I rely on setting power and generally monitoring them that I lose using plugs under ANR. With an 1820 on the front of an Ag plane though, then doubled up is basically a requirement.
 
Pilots should wear foamies and a headset. Always. Your hearing is not worth screwing around with.
 
Henning said:
I tried the double up a couple of times before, and in typical planes, I find it too quiet as well. There are nuance sounds of the engine I rely on setting power and generally monitoring them that I lose using plugs under ANR. With an 1820 on the front of an Ag plane though, then doubled up is basically a requirement.
Click to expand...

You should try these things. They are great for getting a little extra audio if you need them.

http://www.surefire.com/ep3-sonic-defenders.html
 
I play the stereo in my car far louder than I subject myself to in a plane, so I don't tend to worry about it. I'm 50 and my hearing is still fine, there are other, more critical, parts of me that will likely fail long before my hearing. :lol: As long as I wear out the critical parts before the peripheral parts, I'm good with the terminal result. ;)
 
I double up when shooting high power (use ear plugs and passive headset).

But flying with foam ear plugs under my david clark ANR headset doesn't work for me.
 
Stewartb said:
So a sound wave enters an ear cup at approx 768mph and in the space of a millimeter or two a microphone hears the sound, processes the frequency, and signals a speaker to create an opposite sound wave?
Click to expand...

Yes, that's right and the remaining energy is reduced dramatically as a result, not doubled.

http://www.lightspeedaviation.com/c...-101-A-Tutorial-on-Active-Noise-Reduction.htm

Maybe it's envisioning things as a wave that's confusing you? Think of it instead as pressure changes. Those waveforms you see are changes in pressure from ambient. So the high side of that wave is higher pressure and the lower side is lower pressure. When the high side of the wave is passing by the speaker in the headset moves away from your ear, effectively removing that pressure. When the low side is passing by it moves the speaker toward your ear, adding energy. It does this thousands of times per second (just like a speaker reproducing a singer vibrates thousands of times per second) and literally removes (from a physics standpoint they are absorbed by the speaker that is creating the opposite wave) the pressure waves before they hit your ear.

There, now you've heard it from a scientist. :)
 
Last edited:
You must log in or register to reply here.
Back
Top