Want best speech intelligibility in flight and long term hearing protection? Why I'm switching to ANR from a light foam plug passive headset, and you should too.

[aviatoreb]

8 hours ago, Hank said:

Roll 'em briefly in your (gloved) fingers before putting 'em in. My coldest takeoff with them has been 8°F in West-by-Gawd, Virginny [surely a nice spring afternoon in your neck of the woods! ].

I bet 8F must'a been colder than a witches breath for an Alabama boy like you!  (My son says colder than a witches breath when he's being funny).

Well its clearly not as cold up here as it used to be.

But - 20's mid day is typical.  But single digits mid day is also typical.  A cold snap might be single digits negative mid day, but -20 or -30F at night.  We don't seem to get -40F like we used to.  (Scientists at NIST have measured a witches breath and a witch has breath as cold as -35F so it hasn't been colder than a witches breath in some time).

BUT - I lie - I don't fly as a minimums rule to myself for safety of a possible off field landing, if it is below zero on the ground which usually means just waiting a couple of hours since it warms up pretty quick from say -20 to 5.

And anyway, I heat the engine and I heat the cabin when it is cold, so I bet its 25-30 in the cabin even if its -20 in the hangar.  And its 70 or more in the engine under its blanket.

I sorta just like my A20's more and I sold my QT's about 5 years ago because I used them for like 6 months then I just stopped.

 

 

[Hank]

6 hours ago, EricJ said:

I've no idea what you're feeling or why, but it isn't the ANR increasing the pressure inside your ear cups.   There is no air pump in your headset that will do that.   If you think there is, just lift the cup a little bit when you feel that to let any pressure out and see what happens.  You may have other things going on.

 

It's not an air pump, but sound is a series of pressure waves. That's the only thing I can think that I feel. But no have ANR headset, use Halos. Love them!

[Hank]

2 minutes ago, aviatoreb said:

I bet 8F must'a been colder than a witches breath for an Alabama boy like you!  (My son says colder than a witches breath when he's being funny).

Wow, witch's "breath"! That's a new, polite one. I've always used / heard a different physiological referent . . . .

[aviatoreb]

40 minutes ago, Hank said:

Wow, witch's "breath"! That's a new, polite one. I've always used / heard a different physiological referent . . . .

I know that version too.  :-0

[midlifeflyer]

How about foam with ANR like the cheap Chinese knockoff UFQ L2?

[Stetson20]

Ear foam inserts- tuck them in your shirt pocket for a bit. If they're tethered, tuck them down the front of your shirt & let your body heat warm them up a few minutes.

I flew helo's in the Army and in the winter, we all stuck the helmet on our knee to warm them before putting them on.

I fly with the Bose A20 for work. After a long flight, I do start to get hot spots.

For the Mooney, I bought a couple Lightspeed Sierra ANR headsets. The Zulu's were too pricey for me. They work well. I haven't taken any really long rides in the Mooney yet.

YMMV and that, plus a dollar (two? inflation!) will get you a cup of coffee...

[N201MKTurbo]

I think of all the assaults on my hearing in my life, I don't think the considerable time spent in a Mooney with David Clarks on is the big dog in the fight. 

200000 miles on motorcycles without a helmet is probably a big one, the wind noise is quite high. Working back in the day at rock concerts, operating power tools without hearing protection, working in the competitive car stereo industry.

Wait, what did you say?

[RobertGary1]

There was a point I was thinking I may have to give up flying/motorcycles etc due to my tinnitus. When the Bose a20 first came out I laughed and wonder what fool would spend $1000 on a headset. But wow what a difference. I no longer get ringing afterwards. As for motorcycles I found airpod pro noise canceling gets rid of a substantial amount of engine and wind noise. Anr really has kept me flying. 

[EricJ]

5 hours ago, Hank said:

It's not an air pump, but sound is a series of pressure waves. That's the only thing I can think that I feel. But no have ANR headset, use Halos. Love them!

Like waves on the ocean, the net level is zero compared to ambient.    You hear the waves, you might feel ambient pressure changing.   The ANR cannot change the ambient pressure.    Squeezing the cups on will do it momentarily, though.

[DXB]

Responding to issues raised by multiple folks below...

(1) @jaylw314 “I was surprised at the claim that low frequency sounds might be more dangerous to hearing loss”   Apologies if I gave this false impression.  My claim is merely that low frequency sounds (<1000 Hz) are encountered at dangerous levels in Mooney cockpits to a far greater degree than higher frequency ones.

(2) @jaylw314 Odd labeling of y axis units on Cessna flyer chart.  I think the correct y-axis is simply decibels here.  The 1.0W/m label should be 1.0W/m^2 (sound intensity), which equals 130db on the scale.   Db is a weird scale calculated as db = 10 • log( I / 1.0 x 10^-12 W/m^2 ). It is designed to span the normal human hearing range of 0 db (threshold of detection) to 130 db (threshold of pain).

(3) @jaylw314 Disparity between multiple cockpit noise profiles and paucity of data.  Interpretation of the Cessna one I posted seems nearly identical to your Comanche profile, so that should provide some confidence that the most dangerous noise is really low frequency in our planes (reposted for comparison below). They look different because a smoothing function has been applied to the former, and the y-axis scale starts at 60db. Most of the damaging exposure happens above 60db, so the Cessna profile is still a reasonable depiction.  I agree it would be helpful to have more data, and the optimal sound protection will be somewhat aircraft specific. E.g. the typical ANR profile may not be optimal for the sound profile of a whiny Rotax engine or a nagging spouse, and turbines seem a different sound animal altogether. But I don’t think it’s too far an extrapolation to suspect that Mooney cockpit noise profile is pretty similar to these two plots. 

(4) @jaylw314 What noise exposure level is damaging?  85 db as a time weighted average over 8 hours is indeed the widely cited OSHA standard for occupational exposure. This standard does not address hazards of potentially much louder sounds over shorter durations, which is what happens in our cockpit environments, or the consequences of less exposure to people with particular susceptibility (discussed below). It’s worth emphasizing that db is a log scale, so a 115db low frequency noise in the cockpit contains 1000-fold (!) the sound energy of the 85db sound.

(5) @jaylw314 Is noise exposure even the dominant factor in hearing loss or is it primarily other factors as we age? It’s complicated. A few background facts: 1. Hearing loss with aging (presbycusis) isn’t inevitable – there are many elderly folks with near normal hearing.  2. Everyone is susceptible to noise induced hearing loss with high level prolonged exposure – the severe consequences from military and industrial environments are well documented. 3. The inner ear damage that causes hearing loss (loss of cochlear hair cells) is a threshold phenomenon – i.e. you can lose a lot of hair cell function as a young person without acquiring a measurable hearing deficit. But once you reach the threshold where it’s measurable, your reserve has been depleted, and effects of any further hair cell loss on hearing are perceptible.  4. There is a large genetic component that governs susceptibility to hair cell loss that is poorly understood, and this is a very active research area where new insights are expected in the coming years.  5. Drugs and other diseases certainly contribute to hair cell damage – e.g. certain chemotherapy drugs, Lasix taken by people with heart disease, the small vessel ischemia in the population with cardiac disease, high dose aspirin, even prolonged continuous use of ibuprofen/naproxen. Despite multiple complex interacting factors, I think the bottom line here is that those of us with significant tinnitus and any of the high frequency loss that it usually indicates have legitimate reason to be worried about further damage of any cause.  

(5) @Hank @Schllc Uncomfortable sensations upon turning on ANR.  Other folks do describe something like this. As @EricJ says, it can’t be real pressure – All the ANR is doing is creating an absence of sound – kinda the opposite phenomenon.  Extreme quiet from an ANR headset can be uncomfortable to people with sensorineural hearing loss due to worsened tinnitus, but that shouldn’t cause a pressure feeling.  Loud sound triggers a protective muscle reflex designed to stiffen the eardrum in order to reduce sound reaching the inner ear (stapedius/tensor tympani reflex), so turning off that reflex by turning on ANR in a noisy environment might also create a perceptible ear sensation initially. Bottom line is I’m really not sure on this one and would like to learn more. 

(6) @Hank Use of non-foam earplugs (e.g. silicone inserts).  Unfortunately, for ear canal inserts, foam plugs are the gold standard for sound deadening (28-33 noise reduction rating) and are measurably superior to silicone or wax (22-23 dB rating) or even custom molds. Dr. Phil correctly says as much on his website in favoring use of the foam inserts that come with the QTs.

 

Edited November 3, 2021 by DXB

[N201MKTurbo]

I kind of like hearing the engine. I swear I can hear the internal parts doing their thing. With ANR I can't hear the engine much at all. The pistons could be flying out the side of the cowl and I would never know it.

[RobertGary1]

32 minutes ago, N201MKTurbo said:

I kind of like hearing the engine. I swear I can hear the internal parts doing their thing. With ANR I can't hear the engine much at all. The pistons could be flying out the side of the cowl and I would never know it.

I feel like I hear more of the engine and valves etc with anr because it dampens the noise of air and exhaust. 

[aviatoreb]

5 minutes ago, RobertGary1 said:

I feel like I hear more of the engine and valves etc with anr because it dampens the noise of air and exhaust. 

I'm with you on that.

[EricJ]

1 hour ago, N201MKTurbo said:

I kind of like hearing the engine. I swear I can hear the internal parts doing their thing. With ANR I can't hear the engine much at all. The pistons could be flying out the side of the cowl and I would never know it.

I think that's why aviation headsets are ANR instead of ANC.   The reduction is really just in the lower frequency regions and typically isn't complete cancellation.   Clanks and clatters and bangs of interest will likely have more than sufficient energy in the higher frequencies to get your attention.   I always use ANR and still hear all kinds of stuff in the engine.

[Schllc]

8 hours ago, DXB said:

Responding to issues raised by multiple folks below...

 

(5) @Hank @Schllc Uncomfortable sensations upon turning on ANR.  Other folks do describe something like this. As @EricJ says, it can’t be real pressure – All the ANR is doing is creating an absence of sound – kinda the opposite phenomenon.  Extreme quiet from an ANR headset can be uncomfortable to people with sensorineural hearing loss due to worsened tinnitus, but that shouldn’t cause a pressure feeling.  Loud sound triggers a protective muscle reflex designed to stiffen the eardrum in order to reduce sound reaching the inner ear (stapedius/tensor tympani reflex), so turning off that reflex by turning on ANR in a noisy environment might also create a perceptible ear sensation initially. Bottom line is I’m really not sure on this one and would like to learn more. 

 

 

I feel no pressure or discomfort from the ANR headset. Other than just the normal clamping of the head and heat that is. 
I don’t have trouble hearing radio calls or passengers either. I just hear them “better” with the clarity  aloft. 
it isn’t until a long flight is concluded and I remove the headsets that the fun starts. 
my tinnitus kicks into turbo and both ears feel almost as if they are throbbing inside 

I would stop short of calling it pain, but it is not comfortable either and it lasts from several hours to several days. It was bad enough to never want to wear the ANR sets if I didn’t have to. 
I even tried some Sony ANR over my CA, but they with sunglasses was too uncomfortable and I didn’t really notice a noise difference.  

[DXB]

33 minutes ago, Schllc said:

I feel no pressure or discomfort from the ANR headset. Other than just the normal calming of the head and heat that is. 
I don’t have trouble hearing radio calls or passengers either. I just hear them “better” with the quality aloft. 
it isn’t until a long flight is concluded and I remove the headsets that the fun starts. 
my tinnitus kicks into turbo and both ears feel almost as if they are throbbing inside 

I would stop short of calling it pain, but it is not comfortable either and it lasts from several hours to several days. It was bad enough to never want to wear the ANR sets if I didn’t have to. 
I even tried some Sony ANR over my QA, but they with sunglasses was too uncomfortable and I didn’t really notice a noise difference.  

Some ANR-related phenomena that may be similar to what you and @Hank describe:

https://www.nytimes.com/wirecutter/blog/how-do-noise-cancelling-headphones-work/

https://www.soundstagesolo.com/index.php/features/178-eardrum-suck-the-mystery-solved

These types of issues are clearly real, though I can find zero scientific literature on it.  I can't imagine how it would be dangerous, but I'm kinda fascinated. These sensations are indeed experienced by a minority of people with ANR. The problems sound like a poorly understood quirk of central auditory processing that happens when ANR suppresses noise in a certain portion of the frequency spectrum.  I'll ask a real hearing scientist and report back at some point.  I hope I don't have the issue, or I'll be putting the A20s I just ordered up for sale on here shortly .

 

[jaylw314]

3 hours ago, DXB said:

(2) @jaylw314 Odd labeling of y axis units on Cessna flyer chart.  I think the correct y-axis is simply decibels here.  The 1.0W/m label should be 1.0W/m^2 (sound intensity), which equals 130db on the scale.   Db is a weird scale calculated as db = 10 • log( I / 1.0 x 10^-12 W/m^2 ). It is designed to span the normal human hearing range of 0 db (threshold of detection) to 130 db (threshold of pain).

(5) @Hank @Schllc Uncomfortable sensations upon turning on ANR.  Other folks do describe something like this. As @EricJ says, it can’t be real pressure – All the ANR is doing is creating an absence of sound – kinda the opposite phenomenon.  Extreme quiet from an ANR headset can be uncomfortable to people with sensorineural hearing loss due to worsened tinnitus, but that shouldn’t cause a pressure feeling.  Loud sound triggers a protective muscle reflex designed to stiffen the eardrum in order to reduce sound reaching the inner ear (stapedius/tensor tympani reflex), so turning off that reflex by turning on ANR in a noisy environment might also create a perceptible ear sensation initially. Bottom line is I’m really not sure on this one and would like to learn more. 

dB should be a dimensionless scale, but the reference measure is important.  SPL should be force per unit area, not power per unit area--there's no way to make the inclusion of watts make sense

IIRC, there's also a muscular reflex that constricts the Eustachian tube with loud noise, and stopping it may relax that muscle (and consequently, a perceived or even actual change in pressure).  Total speculation, of course, but it might explain some of @Hank's experience?

[DXB]

1 hour ago, jaylw314 said:

dB should be a dimensionless scale, but the reference measure is important.  SPL should be force per unit area, not power per unit area--there's no way to make the inclusion of watts make sense

IIRC, there's also a muscular reflex that constricts the Eustachian tube with loud noise, and stopping it may relax that muscle (and consequently, a perceived or even actual change in pressure).  Total speculation, of course, but it might explain some of @Hank's experience?

dB is indeed dimensionless so the label is a bit nonsensical, but I think dB can be expressed as a ratio of power levels or of SPLs.  I think the 130 dB pain threshold is derived from a power level ratio? There does seem to be some variation in how dB is used across human hearing study vs. acoustics, and my understanding of the differences gets fuzzy here.   But on an audiogram, dB is expressed as HL (hearing level), which includes a correction factor at each pure tone frequency to reflect the lack of uniformity in the human  detection thresholds across the frequency spectrum.  So when I see dB SPL instead of HL, I just assume they are expressing dB without the correction factor - I could be wrong on that.

Regarding the tensor tympani and stapedius reflexes (which stabilize the tympanic membrane, not constrict the eustachian tube), that was my hypothesis as well (see point 5 in my discussion above). On further reading, it seems more likely to be some kind of phantom sensation arising from aberrant central processing of sound that only affects some people (links above), but it's poorly understood. 

Edited November 3, 2021 by DXB

[toto]

3 hours ago, EricJ said:

I think that's why aviation headsets are ANR instead of ANC.   The reduction is really just in the lower frequency regions and typically isn't complete cancellation.   Clanks and clatters and bangs of interest will likely have more than sufficient energy in the higher frequencies to get your attention.   I always use ANR and still hear all kinds of stuff in the engine.

I think I need an education on the difference   I always thought that ANR and ANC are just different fancy acronyms for essentially the same thing.

Is there a quick read somewhere on which does what?

[jaylw314]

35 minutes ago, DXB said:

dB is indeed dimensionless so the label is a bit nonsensical, but I think dB can be expressed as a ratio of power levels or of SPLs.  I think the 130 dB pain threshold is derived from a power level ratio? There does seem to be some variation in how dB is used across human hearing study vs. acoustics, and my understanding of the differences gets fuzzy here.   But on an audiogram, dB is expressed as HL (hearing level), which includes a correction factor at each pure tone frequency to reflect the lack of uniformity in the human  detection thresholds across the frequency spectrum.  So when I see dB SPL instead of HL, I just assume they are expressing dB without the correction factor - I could be wrong on that.

Regarding the tensor tympani and stapedius reflexes (which stabilize the tympanic membrane, not constrict the eustachian tube), that was my hypothesis as well (see point 5 in my discussion above). On further reading, it seems more likely to be some kind of phantom sensation arising from aberrant central processing of sound that only affects some people (links above), but it's poorly understood. 

dB for acoustics uses a standard reference of 20 micropascals, which makes sense since SPL is sound pressure level.  AFAIK, HL is still based on SPL, just adjusted for human hearing, I assume this results in a similar result to A-weighting.  watts doesn't make sense since power is not independent of frequency. 

 

[EricJ]

17 minutes ago, toto said:

I think I need an education on the difference   I always thought that ANR and ANC are just different fancy acronyms for essentially the same thing.

Is there a quick read somewhere on which does what?

In marketing they're often used almost interchangeably, so, yeah, from some perspectives the terms may be used that way.   In engineering applications there are a lot of differences in various approaches, etc., and there are systems that can or attempt to effectively cancel noise in many environments compared to just reduce it.   As has been shown in this thread, aviation headsets don't do that, and reduce noise in the lower parts of the audible frequencies and don't do nearly as much in the higher frequencies.   Such systems are usually distinguished as ANC (adaptive noise cancelling) and ANR (adaptive noise reduction).    In aviation I think ANR (reduction rather than cancellation) is used intentionally so that we don't miss warning chimes and horns from cabin/cockpit speakers and other useful audible cues.    An actual ANC system in an aviation headset would imho be dangerous.

Most "ANR" systems are implemented with small analog circuits, which are relatively simple and inexpensive to implement.   ANC systems are more frequently digital in order to achieve higher performance.

Edited November 3, 2021 by EricJ

[Will.iam]

Has anybody tried the CQ1? 
https://cqheadset.com/

would sure like to get a pirep on these. They might be my next headset to try. 

[Andy95W]

14 hours ago, Will.iam said:

Has anybody tried the CQ1? 
https://cqheadset.com/

would sure like to get a pirep on these. They might be my next headset to try. 

Looks exactly like the QT Halo, but more expensive.  And I’ll bet the owner of the company isn’t a Mooney owner like Phil @pmccand (yes, he’s also a MooneySpace member).

https://www.quiettechnologies.com

[DXB]

This may address @midlifeflyer 's question...

I wondered why the superior comfort and high frequency deadening of foam ear canal insert-based headsets haven't been effectively combined with the superior low frequency performance of ANR. I think part of the answer is that effective ANR for low frequency relies in large part on a microphone inside the ear cup to drive the cancelling wave generation algorithm. The insert-based headsets may not have room for such a microphone.  There is this Bose earbud-based headset and a couple cheap knockoffs on the market that I suspect use an external microphone to drive ANR, but their performance does not seem suitable for the low frequency-biased noise profiles of our planes. They are marketed for jets exclusively, and I wonder if they're really any better than foam inserts in that environment.

https://www.bose.com/en_us/products/headphones/aviation_headsets/proflight-aviation-headset-ii.html#v=proflight_hdst_ii_portable

Edited November 8, 2021 by DXB

[aviatoreb]

18 hours ago, Andy95W said:

Looks exactly like the QT Halo, but more expensive.  And I’ll bet the owner of the company isn’t a Mooney owner like Phil @pmccand (yes, he’s also a MooneySpace member).

https://www.quiettechnologies.com

Yeah - it looks EXACTLY the same to the point of being a rip off?

Availability of blue tooth though is nice.