FAA paper Noise Attenuation Properties of Noise-Canceling Headsets

[Jim Macklin]

InFO

Information for Operators

U.S. Department InFO 07001

of Transportation DATE: 1/5/07

Federal Aviation Flight Standards Service

Administration Washington, DC

http://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_safety/info

An InFO contains valuable information for operators that
should help them meet certain administrative, regulatory, or
operational requirements with relatively low urgency or
impact on safety.

SUBJECT: Noise Attenuation Properties of Noise-Canceling
Headsets

Purpose: This InFO alerts operators, directors of operations
(DOs), chief pilots, and flight crewmembers who may be using
noise-canceling headsets of the potential for misdetection
of audible alarms and other environmental sounds.

Background: Ordinary (non-noise-canceling) headsets reduce
ambient noise levels through a physical means by providing
some acoustical quieting. Noise-canceling headsets cancel
noise through a combination of physical means and electronic
means. While this technology can have many beneficial
effects such as providing clearer communications, reduced
pilot fatigue, and added comfort, electronic attenuation of
important environmental sounds and alarms may occur.

Discussion: Noise-canceling headsets are most effective over
a narrow frequency range, but the specific frequencies may
vary by make and model. Also, these electronically
attenuated frequencies are often proprietary to the
manufacturer and may not be publicly available. Therefore,
it is difficult to assess any effects the headsets may have
on discerning environmental sounds such as:

.. Vital communications between flight crewmembers or flight
attendants, other than those attainable through interphone
operations;


.. Abnormal mechanical noises or abnormal engine sounds;


.. Audible alarms other than those discernible by electronic
means;


.. Vibrations or wind noises; or


.. Other aircraft during ground operations.

Recommended Action: Operators, DOs, chief pilots, and
crewmembers of aircraft should evaluate their use of
noise-canceling headsets. The FAA recommends sampling the
available manufactured makes and models when performing such
evaluations, since performance and attenuation properties
vary. Evaluations should be conducted while both on the
ground and in flight during normal operating conditions to
ascertain if any audible alarms or other environmental
sounds, or combinations thereof, can be detected while
electronic noise attenuation is on and active. If any
audible alarms or environmental sounds cannot be discerned,
operators should elect to find other solutions to discern
such alarms or sounds, or discontinue the use of
noise-canceling headsets.

Approved by: AFS-200

[Thomas Borchert]

Jim,

> Operators, DOs, chief pilots, and
> crewmembers of aircraft should evaluate their use of
> noise-canceling headsets.
>

Done that. It's a complete non-issue. I wish they were that good...

--
Thomas Borchert (EDDH)

[Ron Natalie]

Jim Macklin wrote:
> InFO
>
> Information for Operators
>
> U.S. Department InFO 07001
>
> of Transportation DATE: 1/5/07

Somebody wasted my tax dollars coming up with this piece
of "obvious" drivel? Try them on and see what you can
hear?

I need to get some FAA contracts going.

[[email protected][_1_]]

> Somebody wasted my tax dollars coming up with this piece
> of "obvious" drivel? Try them on and see what you can
> hear?

Phhhhtttt. These guys are pikers, Ron. Hell, at least they're
studying something quasi-useful.

Here's a good one: There are "government studies" going on nationwide
-- to the tune of tens of millions of taxpayer dollars -- trying to
figure out why people are FAT, as if this is some sort of mystery.

Closer to (my) home, let's talk about the hundreds of thousands of
dollars spent on "environmental impact studies" for our runway
extension in Iowa City. As if any one of us couldn't have written a
fact-filled report on any given weekend, describing the effect of
adding 1000 feet of pavement to the end of the runway.

Or, perhaps, we should talk about the University of Iowa's "driving
simulator" that has cost millions, and generated little real science?
Or their ongoing millions in grants to develop "synthetic vision" --
when it's already for sale in ads in every aviation magazine.

The more you look, the sicker you become. It's best not to think about
it.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Matt Barrow]

> wrote in message
ups.com...
>> Somebody wasted my tax dollars coming up with this piece
>> of "obvious" drivel? Try them on and see what you can
>> hear?
>
> Phhhhtttt. These guys are pikers, Ron. Hell, at least they're
> studying something quasi-useful.
>
> Here's a good one: There are "government studies" going on nationwide
> -- to the tune of tens of millions of taxpayer dollars -- trying to
> figure out why people are FAT, as if this is some sort of mystery.
>
> Closer to (my) home, let's talk about the hundreds of thousands of
> dollars spent on "environmental impact studies" for our runway
> extension in Iowa City. As if any one of us couldn't have written a
> fact-filled report on any given weekend, describing the effect of
> adding 1000 feet of pavement to the end of the runway.
>
> Or, perhaps, we should talk about the University of Iowa's "driving
> simulator" that has cost millions, and generated little real science?
> Or their ongoing millions in grants to develop "synthetic vision" --
> when it's already for sale in ads in every aviation magazine.
>
> The more you look, the sicker you become. It's best not to think about
> it.

Hey! They gotta **** away $2.7 TRILLION _somehow_. Gotta keep up the
hysterics about deficits, ya' know!

Buying off voters with illegal pork is a lot cheaper than bribing them with
your own money.

[Larry Dighera]

[Possible audible alarm masking by ANR headsets warning snipped]

My old PA28-235 had a visual stall warning system, so there was no
issue there.

Given the fact that it is imperative to wear hearing protecting
headsets while operating most GA aircraft if you don't want to
permanently damage your hearing, perhaps it's time avionics
manufacturers provided warning indicator inputs to their audio panels.
Of course, such a system of providing audible alarms in the PIC's
headset would necessitate other equipment manufacturers providing the
necessary additional outputs.

[Jim[_11_]]

"Ron Natalie" >
> I need to get some FAA contracts going.

Ron,
Sell them something that I can buy that will filter out all the government
drival... something like ANR contact lenses. :) Of course that would
iniciate an AC advising us not to use them during flight...
Jim

[Bill Denton]

Have you looked at any modern audio panels?

Both PS Engineering and Garmin provide 4 +/- unswitched auxiliary inputs...



"Larry Dighera" > wrote in message
...
> [Possible audible alarm masking by ANR headsets warning snipped]
>
> My old PA28-235 had a visual stall warning system, so there was no
> issue there.
>
> Given the fact that it is imperative to wear hearing protecting
> headsets while operating most GA aircraft if you don't want to
> permanently damage your hearing, perhaps it's time avionics
> manufacturers provided warning indicator inputs to their audio panels.
> Of course, such a system of providing audible alarms in the PIC's
> headset would necessitate other equipment manufacturers providing the
> necessary additional outputs.
>

[Cecil Chapman]

I was reading it yesterday,,, I'm with you on this one; what a waste of tax
dollars! :) I printed out my copy to show to my fellow CFI's at my FBO -
we all had a chortle or two. :)

--
=-----
Good Flights!

Cecil E. Chapman
CFI-A, CP-ASEL-IA

Check out my personal flying adventures from my first flight to the
checkride AND the continuing adventures beyond!
Complete with pictures and text at: www.bayareapilot.com

"I fly because it releases my mind from the tyranny of petty things."
- Antoine de Saint-Exupery -

"We who fly, do so for the love of flying. We are alive in the air with
this miracle that lies in our hands and beneath our feet"
- Cecil Day Lewis -

[Larry Dighera]

>"Larry Dighera" > wrote in message
...
>> [Possible audible alarm masking by ANR headsets warning snipped]
>>
>> My old PA28-235 had a visual stall warning system, so there was no
>> issue there.
>>
>> Given the fact that it is imperative to wear hearing protecting
>> headsets while operating most GA aircraft if you don't want to
>> permanently damage your hearing, perhaps it's time avionics
>> manufacturers provided warning indicator inputs to their audio panels.
>> Of course, such a system of providing audible alarms in the PIC's
>> headset would necessitate other equipment manufacturers providing the
>> necessary additional outputs.
>>
>
On Tue, 09 Jan 2007 15:59:19 GMT, "Bill Denton"
> wrote in
>:

>Have you looked at any modern audio panels?

No.

>Both PS Engineering and Garmin provide 4 +/- unswitched auxiliary inputs...
>

That might be an adequate number of inputs in most cases, but it's
still going to require equipment manufacturers of stall warning
systems, autopilots, etc to provide the audio outputs in addition to
their horns and bells.

[Ron Natalie]

Larry Dighera wrote:

> That might be an adequate number of inputs in most cases, but it's
> still going to require equipment manufacturers of stall warning
> systems, autopilots, etc to provide the audio outputs in addition to
> their horns and bells.

Have you ever used an ANR headphone? Most don't attentuate
frequencies that the various alarms (my gear alarm, the cessna
stall party horn, etc...) much more than the passive headphones
do.

Even engine noises are frequently enhanced by ANR. I kept hearing
a clanking noise in the ANR. I pulled off my headphones for a "better
listen" and couldn't hear it. With the ANR I heard it. On landing
I found my exhaust pipe had busted a weld and was flapping around.

>

[Larry Dighera]

On Tue, 09 Jan 2007 12:34:25 -0500, Ron Natalie >
wrote in >:

>Larry Dighera wrote:
>
>> That might be an adequate number of inputs in most cases, but it's
>> still going to require equipment manufacturers of stall warning
>> systems, autopilots, etc to provide the audio outputs in addition to
>> their horns and bells.
>
>Have you ever used an ANR headphone?

Yes. Exclusively since 1996.

>Most don't attentuate frequencies that the various alarms (my gear alarm,
>the cessna stall party horn, etc...) much more than the passive headphones
>do.
>
>Even engine noises are frequently enhanced by ANR. I kept hearing
>a clanking noise in the ANR. I pulled off my headphones for a "better
>listen" and couldn't hear it. With the ANR I heard it. On landing
>I found my exhaust pipe had busted a weld and was flapping around.

Well, that's your experience. It's a data point for sure, but not a
comprehensive study.

If the FAA has found issues as a result of the popularity of ANR
headsets, who am I to dispute it. Certainly most legacy alarms were
tested and approved for use before ANR technology existed, hence my
suggestion for "piping" alarms into the headphone audio in addition to
the ambient cockpit environment.

[B A R R Y[_2_]]

Ron Natalie wrote:
>
> Even engine noises are frequently enhanced by ANR. I kept hearing
> a clanking noise in the ANR. I pulled off my headphones for a "better
> listen" and couldn't hear it. With the ANR I heard it. On landing
> I found my exhaust pipe had busted a weld and was flapping around.

I was able to hear a starter that was stuck engaged WITH the ANR set on.
The sound was not audible by my companion pilot with a non-ANR set, or
me with the headset removed.

[B A R R Y[_2_]]

Jim Macklin wrote:
> InFO
>
> SUBJECT: Noise Attenuation Properties of Noise-Canceling
> Headsets

They are absolutely correct. It's about time someone exposed the myth!

Please send all working ANR headsets, along with a modest $10/set
disposal fee, to me for recycling.

Inoperative sets can be disposed of locally, as they pose no danger.

That is all, please comply...

[Jose[_1_]]

> Please send all working ANR headsets, along with a modest $10/set disposal fee, to me for recycling.

I've Emailed my headset to you. Could you send me a receipt for tax
purposes?

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

[Montblack]

("Jose" wrote)
>> Please send all working ANR headsets, along with a modest $10/set
>> disposal fee, to me for recycling.
>
> I've Emailed my headset to you. Could you send me a receipt for tax
> purposes?


He won't get your e-mail if he's got ..."Active Noise Reduction" filters
enabled. <g>


Montblack

[RK Henry]

On Tue, 9 Jan 2007 07:09:20 -0700, "Matt Barrow"
> wrote:

>
> wrote in message
ups.com...
>>> Somebody wasted my tax dollars coming up with this piece
>>> of "obvious" drivel? Try them on and see what you can
>>> hear?
>>
>> Phhhhtttt. These guys are pikers, Ron. Hell, at least they're
>> studying something quasi-useful.
>>
>> Here's a good one: There are "government studies" going on nationwide
>> -- to the tune of tens of millions of taxpayer dollars -- trying to
>> figure out why people are FAT, as if this is some sort of mystery.
>>
>> Closer to (my) home, let's talk about the hundreds of thousands of
>> dollars spent on "environmental impact studies" for our runway
>> extension in Iowa City. As if any one of us couldn't have written a
>> fact-filled report on any given weekend, describing the effect of
>> adding 1000 feet of pavement to the end of the runway.
>>
>> Or, perhaps, we should talk about the University of Iowa's "driving
>> simulator" that has cost millions, and generated little real science?
>> Or their ongoing millions in grants to develop "synthetic vision" --
>> when it's already for sale in ads in every aviation magazine.
>>
>> The more you look, the sicker you become. It's best not to think about
>> it.
>
>Hey! They gotta **** away $2.7 TRILLION _somehow_. Gotta keep up the
>hysterics about deficits, ya' know!
>
>Buying off voters with illegal pork is a lot cheaper than bribing them with
>your own money.

That's why they need user fees. Taxpayers won't put up with such
waste, so they need to get money from people who have no say in the
matter.

RK Henry

[Thomas Borchert]

Larry,

> If the FAA has found issues as a result of the popularity of ANR
> headsets,
>

I don't think it says that anywhere in that INFO. It says us pilots
should go and find out.

--
Thomas Borchert (EDDH)

[Matt Barrow]

"RK Henry" > wrote in message
...
> On Tue, 9 Jan 2007 07:09:20 -0700, "Matt Barrow"
> > wrote:
>>
>>Hey! They gotta **** away $2.7 TRILLION _somehow_. Gotta keep up the
>>hysterics about deficits, ya' know!
>>
>>Buying off voters with illegal pork is a lot cheaper than bribing them
>>with
>>your own money.
>
> That's why they need user fees. Taxpayers won't put up with such
> waste, so they need to get money from people who have no say in the
> matter.

The taxpayers have been putting up with $$$BILLIONS wasted for DECADES. How
do you think we got to a $2.7 Trillion Federal budget (not to mention
another $2.4 trillion on the state and local level)?

With User Fee's and the right arrangement (significantly different than we
have now), we have much more control over the next generations ATC system
development. See Robert Poole's article on this in the November issue of
_Professional Pilot_ magazine.

--
Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO (MTJ)

[Jay Honeck]

> The sound was not audible by my companion pilot with a non-ANR set, or
> me with the headset removed.

This fits 100% with our experience as well. ANR headphones *enhance*
hearing, and certainly cannot mask the sound of any stall horn/buzzer.
With our Lightspeed Twenty3Gs, we routinely hear things that are
completely inaudible (lost in the noise, actually) without them.

I remember a flight to OSH when we kept hearing a weird whooshing
noise. We were throttled way back to 20 squared, to stay in loose
formation with a slower plane -- something we had rarely done before.
The noise continued, and we simply couldn't figure out what it was.

After a few minutes it finally dawned on us: We were hearing the wind
as it rushed over the fuselage.

Try THAT without ANR headsets!
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Jose[_1_]]

> With User Fee's and the right arrangement (significantly different than we
> have now), we have much more control over the next generations ATC system
> development.

How do you figure? With airlines at the helm and GA paying the bill,
what control do you figure we have?

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

[Larry Dighera]

On Wed, 10 Jan 2007 15:57:24 GMT, Jose >
wrote in >:

>> With User Fee's and the right arrangement (significantly different than we
>> have now), we have much more control over the next generations ATC system
>> development.
>
>How do you figure? With airlines at the helm and GA paying the bill,
>what control do you figure we have?

Not only that, as currently envisioned, aviation user fees will remove
congressional oversight of the FAA ATC budget! Aviation user fees are
clearly another special interest boondoggle to hijack an inherently
governmental function for private control and profit, IMO.

[Newps]

Jay Honeck wrote:

>
> I remember a flight to OSH when we kept hearing a weird whooshing
> noise. We were throttled way back to 20 squared, to stay in loose
> formation with a slower plane -- something we had rarely done before.


You were talking the other day about all the money you save with mogas.
At 20 squared I am indicating about 160 mph in the winter and about
150-155 in the summer, burning 8-8.5 GPH, which for me is about 50 LOP.
What's your speed and fuel burn there?

[B A R R Y[_2_]]

Jose wrote:
>> Please send all working ANR headsets, along with a modest $10/set
>> disposal fee, to me for recycling.
>
> I've Emailed my headset to you. Could you send me a receipt for tax
> purposes?
>


Your headset is still downloading into my replicator. I take it you
PayPal-ed me the fee?

[Jose[_1_]]

> Your headset is still downloading into my replicator. I take it you PayPal-ed me the fee?

No, I sent you a crisp ten dollar bill as an attachment. I know you're
not supposed to send cash through the mail, but this is the internet so
it should be perfectly safe.

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

[Jay Honeck]

> You were talking the other day about all the money you save with mogas.
> At 20 squared I am indicating about 160 mph in the winter and about
> 150-155 in the summer, burning 8-8.5 GPH, which for me is about 50 LOP.
> What's your speed and fuel burn there?

SLOOW. At 20 squared, we were hanging on the prop, trying to fly
formation with our old Warrior -- so probably around 115 knots. Fuel
burn is about the same, though -- maybe 8.5 GPH.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[C J Campbell[_1_]]

On Mon, 8 Jan 2007 20:38:21 -0800, Jim Macklin wrote
(in article >):

> InFO
>
> Information for Operators
>
> U.S. Department InFO 07001
>
> of Transportation DATE: 1/5/07
>
> Federal Aviation Flight Standards Service
>
> Administration Washington, DC
>
>
http://www.faa.gov/other_visit/aviation_industry/airline_operators/airline_saf



This so reminds me of those screamer commercials by bozos trying to sell you
books on how get your share of government grant money and handouts.
Oink-oink.