FAA says noise-cancelling headsets may be hazardous

PHXAvi8tor

PHXAvi8tor

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PHXAvi8tor
Received an FAA Safety Alert this morning via e-mail urging pilots, FBOs, flight schools and all others to test their noise-cancelling headsets to ensure pilots can still hear audible warnings in the cockpit.

One example of an audible warning is the stall-warning horn. But, there are others, as well, especially in more complex aircraft.

All should read the following document, and make some key decisions based on it:

http://www.faa.gov/other_visit/avia...afety/info/all_infos/media/2007/info07001.pdf
 
I was considering buying a DC x11, but one of the concerns I had (other than the price) was that an engine hesitation, or some other noise I would like to hear, might go unnoticed...

Interesting...
 
I saw that and was amused thinking about my particular aircraft. The audible warnings that I would be likely to hear would probably be easily heard despite NC...such as the engine stopping.

All joking aside I believe I can better hear subtle changes in the engine with NC vs. without it.

It is interesting that the FAA released this safety alert apparently without any studies or accidents to, er, punctuate their concern.
 
I can hear other noises in the cockpit better with noise cancelling than without. Gear warning and stall horn are both easily heard.

As an aside, the first time I used a noise cancelling headset I was able to hear a bad bearing on the nose gear that I could not hear without them. Sold me on the benefits.
 
This is a little silly. ANR only cancels low frequency noise.

It's the passive component of a headset that is going to cut the sounds of any audible alerts. Are they warning against using headsets in general?

They might want to put out another warning: You might not see the stall light in birds like mine if you're under the hood.
 
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There's a budget problem, and the FAA wastes dollars to produce something like this? The program itself is useful, but this particular topic isn't news to anyone who's looked at ANR headsets, ever.
 
Timely report. Glad they are on top of the whole ANR thing before people widely adopted those headsets. This will stop us from getting those deadly ANR headset where we will be missing warning horn noises and such.

PPPHHHOOOOEEEEYYY!!!!
 
sbonek said:
I was considering buying a DC x11, but one of the concerns I had (other than the price) was that an engine hesitation, or some other noise I would like to hear, might go unnoticed...

Interesting...
Click to expand...

You can actually hear the engine a LOT better WITH ANR. It basically just gets rid of the big rumble, allowing you to hear what's really going on. With ANR, I can hear valves clicking in time, air rushing past the plane, etc.

It is a good idea to test and see if you can hear stall/gear warnings, but I doubt any buzzers like that would be any less audible with ANR than PNR. FAA needs to get a clue, again.
 
PHXAvi8tor said:
Received an FAA Safety Alert this morning via e-mail urging pilots, FBOs, flight schools and all others to test their noise-cancelling headsets to ensure pilots can still hear audible warnings in the cockpit.
Click to expand...

I received that too and my reaction was, "BOOOOOOGUS!" I'm going to need convincing on that one. Most of the audible warnings in the Bo go through the intercom anyway, but even those that don't (gear warning for example) can easily be heard. Wonder what happened to cause that alert?
 
ANR works by cancelling out the steady noise. when that noise changes, like if the engine coughs, or something lets lose, you will hear it. right?

Ive never had a problem hearing stall/gear warning horns with my Lightspeeds.
 
I never have a problem hearing the RG's cabin alerts through my Lightspeed Thirty 3Gs. The stall warning horn is plenty loud enough.

Now, if I can just figure out why the stall warning keeps going off and on rapidly when I make a final approach! :confused:
 
That sounds mostly like BS to me. I've been flying with Bose since the new version came out a few years ago, and with Lightspeed before that. I have no trouble hearing warning horns in either fixed-wing or helicopters (and testing the low rpm warning light and horn is the very last thing I do before pulling pitch for takeoff for every departure).

The only concern I have is whether I would hear a subtle rpm change, a concern shared by other rotorheads.
 
This alert is complete BS. I've been flying with ANR since the first Bose came out - as others have posted you can hear what's going on in the cockpit much better with ANR than with passive noice-cancelling headsets that simply make everything quieter. ANR deals with the low-freq rumbles, not the mid-tones or higher where all the alarms and alerts are. And the engine makes plenty of mid-tone noises, too, so there's no problem noticing an anomaly.

Maybe someone at the FAA got one of those consumer Bose sets that they sell for passengers on the airliners? Not much reciprocating rumble on those any more, so I speculate the consumer version damps noise in a higher frequency range.

Regards,
Joe
 
TMetzinger said:
There's a budget problem, and the FAA wastes dollars to produce something like this? T.
Click to expand...
My guess is that because of the budget issues, they dredged up a scare piece from the early days of ANR when no one was using them, even less people understood them, and the combination led to this completely unwarranted concern.

In fact, the blurb sounds awful familiar, like I've read it before.
 
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I wonder if some pilot blamed his accident on NC headsets?
 
RotaryWingBob said:
The only concern I have is whether I would hear a subtle rpm change, a concern shared by other rotorheads.
Click to expand...

Bob, you can feel the RPM changes. At least I can. There is a noticeable difference in engine noise (and vibration) when i turn the blue knob. No?
 
Joe B said:
Maybe someone at the FAA got one of those consumer Bose sets that they sell for passengers on the airliners? Not much reciprocating rumble on those any more, so I speculate the consumer version damps noise in a higher frequency range.

Regards,
Joe
Click to expand...

I've got a pair (two, actually) of those Bose Quiet Comfort 2 headsets. They take out the engine noise in an airliner almost completely. I love them. I've told a friend who works for Bose that I'd rather leave my laptop home on a trip than those QC2 headsets.
 
This reminds me of the Parker Hannefin death threat letter, claiming we will die if we use one of their vacuum pumps.
 
Michael said:
Bob, you can feel the RPM changes. At least I can. There is a noticeable difference in engine noise (and vibration) when i turn the blue knob. No?
Click to expand...

No blue knob on a helicopter. Most modern helicopters have governors which are supposed to hold the erpm to a very tight tolerance. For example, our R22 holds it between 101 and 104%, and the R44 101-102%. There are certain situations where the rrpm (and erpm) might decay slowly (high density altitude operation, for example). The concern is whether the pilot can hear that happen with noise cancelation. The jury is pretty well still out on that one.

Low rrpm can (and will) kill you if the rotor blades stall. High rrpm and erpm may damage the rotor system and the engine as well.
 
I heard somewhere that the ANR headsets acutally hurt your hearing later on.
 
I can barely hear the stall horn in a Tobago or the gear horn in a Cardinal with my Lightspeads on.
 
The extra cost of ANR would keep me from hearing around 3 hours of ANY aircraft noise:rolleyes:.
 
Trixie said:
I heard somewhere that the ANR headsets acutally hurt your hearing later on.
Click to expand...

Could you look into this and point me to that? I have a nice Bose set which I love, but eventual loss of hearing is enough to make me reconsider.

P
 
I'm no audio expert. Nor do I own one of those fancy ANR headsets. I know how my ten million year old set of David Clarks work. They clamp your head so tight and have so much foam that they simply cut decibels. I'm willing to bet that they do this across the frequency range somewhat evenly. I may not be able to hear a quiet noise because they cut so much out.

My understanding of ANR headsets is that they cut out the low frequencies. They have less passive protection which actually leads to better hearing of some of the mid and high range frequencies. If you have some type of audible warning that is of a low frequency it may be an issue. Otherwise--I doubt it.

The primary problem with the passive headset is that it has no intelligence. It was designed to just cut noise as much as possible to the point to where the person wearing it does not get a headache or ear damage. If there is a quiet noise that starts to develop that could signify a pending mechanical problem you probably won't hear it with passive. You might hear it earlier with ANR because certain frequencies can be heard better.

There is of course a curve per say of what ANR cancels out of the audio spectrum that you would hear with your passive headset. I'm willing to bet that this curve is mostly real low frequency crap that isn't of much use to you. Once you get into the higher frequencies you will actually hear some things *BETTER* with ANR because there is less passive protection and the ANR is not cancelling those frequencies out.

I'm saying bull**** to that report.

ANR overall leads to a safer flight. Of course like anything there may be a case or two where it doesn't. Just like you might be better off without your seatbelt on if a sharp poll slams through your windshield and through your body. But-- looking at the big picture..I'd much rather have my seatbelt on in an unknown accident the same as how I'd much rather have an ANR headset.
 
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Trixie said:
I heard somewhere that the ANR headsets acutally hurt your hearing later on.
Click to expand...

Not true - it's a common misperception that since the ANR headsets actually pump in "anti-noise" (the out of phase signal to the outside noise), that somehow this "anti-noise" exerts additional sound pressure on your ears.

Your ears respond to the sound pressure waves entering the ear canal. If multiple waves cancel out, resulting in a reduced amplitude (which is what happens with ANR), your eardrums move LESS distance in-and-out. Period, end of story, this can be confirmed with a jumprope and a couple of ten-year-olds.

Now, certain low frequencies at high pressure levels will damage your hearing and you'll never hear them. You will definitely feel them though, and they don't happen in airplanes.

So, use your ANR headsets without fear of ill effects - if your ears tell you something is loud or soft, that's what matters.
 
TMetzinger said:
Not true - it's a common misperception that since the ANR headsets actually pump in "anti-noise" (the out of phase signal to the outside noise), that somehow this "anti-noise" exerts additional sound pressure on your ears.
Click to expand...

I'd also heard that they had problems, but not for the reason you give above (which you explained very well). It had something to do with the frequency response. I think the gist was that they don't have the bandwidth to cancel the higher frequencies, so those end up getting through more than with a passive set and you end up with more damage in the long run.

I can't find the reference now, and frankly it seems a bit fishy. It's probably an OWT. Does anybody know more about this?

Chris
 
I think that might be true in the case where the ANR fails. But in that case, you wouldn't be talking about hours and hours of exposure, because you'd get the headset repaired/replaced. I have a set of the foam plugs that I can wear inside mine if the ANR failed.

When the ANR is working, I believe (at least looking at the graphs of my DC 10-13 passives and my LS 30-3G actives) the ANR headsets are more effective across the entire frequency range.
 
fwiw i was flying the 421 tonight and as we were descending in i heard this faint beeping sound. asked the boss what that was, he didnt hear anything. he had my lightspeeds on but ANR off. I took off my headsets and heard nothing.



it was the beginnings of the gear warning horn, manifold pressure was just at the threshold to make it go.
 
tonycondon said:
fwiw i was flying the 421 tonight and as we were descending in i heard this faint beeping sound. asked the boss what that was, he didnt hear anything. he had my lightspeeds on but ANR off. I took off my headsets and heard nothing.



it was the beginnings of the gear warning horn, manifold pressure was just at the threshold to make it go.
Click to expand...

So he was wearing ANR without the ANR turned on. What were you wearing that allowed you to hear it?
 
Well reading some of the comments I feel the need to chime in.
I am a new student pilot at 65yrs old. Finally working on my dream. Having a blast and being challenged a bunch.
So I rush out and buy the David Clark H10 figureing hey you can go wrong. I love them, real comfortable great audio quality.
So all is well until my first lesson on stalls. You guessed it can’t hear the stall horn at all. Had to lift one ear out of the headset to hear it.
So not sure what the next move.
Bottom line do your homework on head sets and all other tools needed for flying.
 
ParkerB said:
So all is well until my first lesson on stalls. You guessed it can’t hear the stall horn at all. Had to lift one ear out of the headset to hear it.
So not sure what the next move.
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That's a bit surprising. I've been using ANR for about 20 years and have never had an issue hearing stall warnings, gear warnings, the slight difference in engine sounds when doing mag checks, power increases and changes or anything else I'm aware of (and I listed some precisely because I have heard them). Have you done your medical yet to rule out a hearing issue, or even if you did, the FAA medical test can be pretty basic, so you might check if it's perhaps some natural hearing reduction at certain frequencies, something pretty common at your advanced age*

[* :D PS. I'm older than you. Welcome to our mildly dysfunctional family)]
 
ParkerB said:
Well reading some of the comments I feel the need to chime in.
I am a new student pilot at 65yrs old. Finally working on my dream. Having a blast and being challenged a bunch.
So I rush out and buy the David Clark H10 figureing hey you can go wrong. I love them, real comfortable great audio quality.
So all is well until my first lesson on stalls. You guessed it can’t hear the stall horn at all. Had to lift one ear out of the headset to hear it.
So not sure what the next move.
Bottom line do your homework on head sets and all other tools needed for flying.
Click to expand...
For the flight test, take it off during stall demos, slow flight, etc. For real life, if you need a stall warning system in the planes you'll likely be flying you're in real trouble.
 
ParkerB said:
Well reading some of the comments I feel the need to chime in.
I am a new student pilot at 65yrs old. Finally working on my dream. Having a blast and being challenged a bunch.
So I rush out and buy the David Clark H10 figureing hey you can go wrong. I love them, real comfortable great audio quality.
So all is well until my first lesson on stalls. You guessed it can’t hear the stall horn at all. Had to lift one ear out of the headset to hear it.
So not sure what the next move.
Bottom line do your homework on head sets and all other tools needed for flying.
Click to expand...
Welcome to POA ! Good luck with your training!
 
Back in the olden days, when I learned to fly, there was none of this ANR nonsense. You had a mic on a chrome plated clip on the panel, and an overhead speaker as God intended. That's how it was, and that's how it should always be. You don't see the Amish using them do you? Neither should you.

Federal Aviation Administration: Protecting pilots from technology since 1958.
 
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