Flying by reference to sound

[201er]

Had to send my Halo headset out for a repair (BTW Phil is awesome, did it at no charge) so I got stuck having to use the Bose. Had every seat in the Mooney full and my wife refused to trade my her halo. I didn't realize until shortly after takeoff, just how much I have gotten used to flying my plane by reference to sound! I felt like something important was missing. My speed control just wasn't quite there because I didn't have my usual audible cross reference of wind noise.

The excessive noise cancellation and noise distortion of the Bose prevented me from getting the audible picture I had become accustomed to. So it wasn't just that it didn't give me the familiar hum of the engine and reassurance that it was still firing, but the lack of wind-noise was also a problem.

I had never really thought about this before because I began using the Halo shortly after getting my Mooney. But after flying my bird for years being used to hearing it a certain way, it threw me off when it didn't sound the same. Just something to think about.

[Hank]

It took a little getting used to the different sound when I bought my Halos. I'd had the plane about three years at the time. All it took was my first trip, HTW-->FXE to make me a true believer! 6.2 hours of comfort.

Now I can tell when one plug isn't set quite right, and give it a little extra push. But sound is an important part. Wore a friend's Bose riding right seat in his Bo, it was just all wrong when the white noise first came on, felt like it was pressurizing against my ears. Sure was nice getting back to my Halos!

[ArtVandelay]

I don't what you mean by white noise, but I don't hear anything with my A20s. You just put them on and the noise goes away. If you want more noise, just put on glasses, they will pull the muffs a little from you head giving you more a noise.

I've got the thicker glass so I don't hear wind, but the engine noise is enough @90dB.

[Marauder]

I switched back from the Halos during the summer to the Zulus. I found the ANR easier to discern the minor noise changes that I couldn't detect with the Halos. The lower engine drone with the Halos covered up other things like the wind noise and even some prop pitch changes.

 

It comes down to what you are accustomed to and the state of hearing. I switched from passive David Clark's to the first set of Telex ANRs back in the 90s and hadn't flown passive until I bought the Halos.

 

 

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[ryoder]

Clarity Aloft.  Works great.  Lowers temperature and doesn't hurt your ears.

[aviatoreb]

I used my halos for several years but at some point I just switched back to my Bose headsets and sold my halos.  I like my bose more.

[yvesg]

Mike, your statement is definitely confirming what I thought about you: you are a bird!

Yves

[cliffy]

Although I can't find it right now I just got an email from the Feds (one of those cautions not quite up to an AD). Seems they're getting worried about noise cancelling headsets blocking out electronic warnings in cockpits and engine sounds.

[M016576]

12 hours ago, cliffy said:

Although I can't find it right now I just got an email from the Feds (one of those cautions not quite up to an AD). Seems they're getting worried about noise cancelling headsets blocking out electronic warnings in cockpits and engine sounds.

I received that email from the FAA too... Makes me wonder if this thread is a result of that circular.

[201er]

No, but it's interesting.

Can you guys hear the stall warning with ANR?

[Marauder]

No, but it's interesting.

Can you guys hear the stall warning with ANR?

Absolutely. I can also hear the Aspen's altitude warnings.

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[HRM]

On November 6, 2015 at 9:16:22 PM, 201er said:

The excessive noise cancellation and noise distortion of the Bose prevented me from getting the audible picture I had become accustomed to. So it wasn't just that it didn't give me the familiar hum of the engine and reassurance that it was still firing, but the lack of wind-noise was also a problem.

I had never really thought about this before because I began using the Halo shortly after getting my Mooney. But after flying my bird for years being used to hearing it a certain way, it threw me off when it didn't sound the same. Just something to think about.

It sounds like you have hearing loss. This is different from being unable to comprehend what is said. The latter occurs with age, the former from genetics and failure to protect the ears.

When I first started flying with my A20s I thought the silence was eerie, but now I have become accustomed to them and can hear everything I need to hear. The engine has a specific sound and vibration and all of the audible alerts in my cockpit are easy for me to detect. The radio is the best part, ATC comes in as if the engine was off, totally LC. 

I will confess, however, that my most often used phrase is 'Say again." I am not getting any younger you know 

[Shadrach]

22 hours ago, cliffy said:

Although I can't find it right now I just got an email from the Feds (one of those cautions not quite up to an AD). Seems they're getting worried about noise cancelling headsets blocking out electronic warnings in cockpits and engine sounds.

That's rather silly of them. I can actually hear engine noises with both my X's and A20s as opposed to just the muted drone I've gotten with passive only headsets. With the heater on, I can crisply hear the valve-train as well as other engine and airframe noises. It seems to me that almost anything that a pilot would need/want to hear is at frequency range far higher than what ANR headsets cancel. The idea that a gear or stall horn is less audible with ANR headsets is likely the opposite of what is really going on.

 

[Shadrach]

I would think that wind noise would be just as audible if not more with ANR. I can hear gusts and strong crosswind when sitting on the ground with my ANRs, the wind is at a higher freq than what ANR cancels out. The only time I find wind noise is really obvious in my plane is at or near Vne (less so now that the "clothes line" ADF antenna is gone). Perhaps Mike has an antenna that wistles, acting as a "telltale".  I have never used wind noise to fly a plane. I did fly through a shear once that was so bad I could hear parts of the airframe vibrate.

[201er]

3 hours ago, Shadrach said:

I would think that wind noise would be just as audible if not more with ANR. I can hear gusts and strong crosswind when sitting on the ground with my ANRs, the wind is at a higher freq than what ANR cancels out. The only time I find wind noise is really obvious in my plane is at or near Vne (less so now that the "clothes line" ADF antenna is gone). Perhaps Mike has an antenna that wistles, acting as a "telltale".  I have never used wind noise to fly a plane. I did fly through a shear once that was so bad I could hear parts of the airframe vibrate.

I started in gliders and you learn to fly speed by pitch and sound. There's no engine, so wind noise is very obvious. Reduced wind noise also alerts you to an impending stall. It's the same in airplanes but more subtle. I didn't realize this until I had to change headsets for a day.

[HRM]

45 minutes ago, 201er said:

I started in gliders and you learn to fly speed by pitch and sound. There's no engine, so wind noise is very obvious. Reduced wind noise also alerts you to an impending stall. It's the same in airplanes but more subtle. I didn't realize this until I had to change headsets for a day.

Using the same headset is key. What you do over time is develop an accommodation to the normal sound signature of your plane. When that alters, you may have a problem. Not unlike a dog that will sleep through kids running around, TV blaring, etc., but let someone walk up to the front door and the barking begins.

[Marauder]

45 minutes ago, 201er said: I started in gliders and you learn to fly speed by pitch and sound. There's no engine, so wind noise is very obvious. Reduced wind noise also alerts you to an impending stall. It's the same in airplanes but more subtle. I didn't realize this until I had to change headsets for a day.

Using the same headset is key. What you do over time is develop an accommodation to the normal sound signature of your plane. When that alters, you may have a problem. Not unlike a dog that will sleep through kids running around, TV blaring, etc., but let someone walk up to the front door and the barking begins.

Great observation! Owning the same plane for years, I have gone through a series of headsets. And ever time I switched brands or styles, the first flight was always, "that doesn't sound right!"

And each brand seems to allow or attenuate some noises over others. My original Clark passives were just a solid drone. The Telex ANR from the 90s seemed to amplify the the low rumbling sound of the engine, the Clark ANR picked up more mid range stuff, the Telex Stratus 50 seemed to hum more, the Lightspeed picks up a lot more of the wind noise and the Halos definitely blocked everything about the same level.

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[M016576]

Isn't the Halo just a set of earplugs with a speaker in the middle and a boom mic attached?

If I understand all this correctly, "Passive Noise Cancellation" is a fancy way of saying "I'm physically blocking sound from your ear drum," right?  "Active Noise Cancellation" involves receiving sounds and phase-shifting them 180 degrees, then rebroadcasting to actually "kill" the noise.   The article below mentions that active sound cancellation can decrease noise by 40dB vice passive which is good to about 20dB

I use the Air Force approved solution at work (helmet plus foamies) and an old Bose series II active in the mooney.  I prefer the old Bose's- I feel like I hear more of what I want to hear (to include some wind noise, stall horns, etc). To each their own.  I flew with a guy once that wanted to use the hand mic and overhead speakers... Old school.

the link- 

http://electronics.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm

 

[Hank]

34 minutes ago, M016576 said:

Isn't the Halo just a set of earplugs with a speaker in the middle and a boom mic attached?

If I understand all this correctly, "Passive Noise Cancellation" is a fancy way of saying "I'm physically blocking sound from your ear drum," right?  "Active Noise Cancellation" involves receiving sounds and phase-shifting them 180 degrees, then rebroadcasting to actually "kill" the noise.   The article below mentions that active sound cancellation can decrease noise by 40dB vice passive which is good to about 20dB

I use the Air Force approved solution at work (helmet plus foamies) and an old Bose series II active in the mooney.  I prefer the old Bose's- I feel like I hear more of what I want to hear (to include some wind noise, stall horns, etc). To each their own.  I flew with a guy once that wanted to use the hand mic and overhead speakers... Old school.

the link- 

http://electronics.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm

 

No, you have just describe Clarity Aloft headsets.

Halos put the speaker on the back, behind your head [nothing goes on top], and runs a sound tube from the rear speakers through the earplug.

I won't swear to it, but I remember seeing many passive sets advertising 25-30dB noise reduction. Halos advertise 30-45 dB noise reduction if you put the plugs into your ears properly. Across the full sound spectrum, unlike ANR which concentrates on only part of the noise, leaving the passive protection of the ear cups to do the rest of it.

http://www.quiettechnologies.com/index.php?route=product/product&path=66_59&product_id=51

[Shadrach]

15 minutes ago, Hank said:

No, you have just describe Clarity Aloft headsets.

Halos put the speaker on the back, behind your head [nothing goes on top], and runs a sound tube from the rear speakers through the earplug.

I won't swear to it, but I remember seeing many passive sets advertising 25-30dB noise reduction. Halos advertise 30-45 dB noise reduction if you put the plugs into your ears properly. Across the full sound spectrum, unlike ANR which concentrates on only part of the noise, leaving the passive protection of the ear cups to do the rest of it.

http://www.quiettechnologies.com/index.php?route=product/product&path=66_59&product_id=51

I think there is some confusion about "the rest of it". I don't think it's a good idea to block out "the rest of it". Most of the volume in a recip is low frequency from prop and exhaust. What high frequency sounds should be blocked? Mechanicals? Wind? Various alerts and warnings? I don't think these should be blocked and I feel like the X's and A20s make these sounds more audible.

[M016576]

2 hours ago, Hank said:

No, you have just describe Clarity Aloft headsets.

Halos put the speaker on the back, behind your head [nothing goes on top], and runs a sound tube from the rear speakers through the earplug.

I won't swear to it, but I remember seeing many passive sets advertising 25-30dB noise reduction. Halos advertise 30-45 dB noise reduction if you put the plugs into your ears properly. Across the full sound spectrum, unlike ANR which concentrates on only part of the noise, leaving the passive protection of the ear cups to do the rest of it.

http://www.quiettechnologies.com/index.php?route=product/product&path=66_59&product_id=51

Gotcha- I didn't realize those were two different products (halo/clarity aloft).  by mounting the speaker behind your head, does that make for a more effective ear bud (i.e., more sound blocking material in the plug)?  Still, from the looks of it they seem to just be blocking sound out while providing a clear avenue for the radios.  Am I missing something?

[201er]

1 hour ago, pmccand said:

The standard yellow roll up foams have low frequency noise attenuation of about 25dB at 125Hz , but there are better (softer) foams available that attenuate in the 30+dB range.  (Btw, we have these softer foamies available) These softer foams are more in line with the latest quieting capabilities of the mega $AMU ANR headsets in the prop frequency range. 

Thanks for the information Phil. Which foams are you referring to? Were these included with the Halo or something new that you offer?

[mike_elliott]

1 hour ago, pmccand said:

Perhaps y'all would be really interested in this really nice piece of advertising/informative literature from 3M corporation on hearing protectors including everything you would want to know and more about ear muffs, ear plugs, noise and hearing damage.  It gives a good (great) synopsis of ear protection data for the average joe.  It is a really good read for those interested in this general topic.  It should clear up a few questions from above.

Skip to page 9 for a LONG list of noise protection devices which end around page 44.  At 44 and beyond, there is a good explanation of what noise does to you physically.  Finally, the last part shows a COMPLETE summary of the amount of noise protection, not only in NRR's but in median (average) data across frequencies.  Engine prop and exhaust noise is greatest at 90 -125Hz so those data are of particular interest to pilots.  Wind noise is broad band, and has the greatest impact at the higher frequencies.

The standard yellow roll up foams have low frequency noise attenuation of about 25dB at 125Hz , but there are better (softer) foams available that attenuate in the 30+dB range.  (Btw, we have these softer foamies available) These softer foams are more in line with the latest quieting capabilities of the mega $AMU ANR headsets in the prop frequency range.  

http://multimedia.3m.com/mws/media/711107O/3m-hearing-protection-brochure.pdf

Cheers y'all

Phil Mc

EAR (In Indy) used to sponsor me in a previous life as a racer, and I spent a great deal of time at their facilities undergoing sound testing, back when Cabot Corp owned them prior to 3M. They make great stuff, not only from a hearing protection standpoint, but from a vibration dampening prospective also. Phil, how about donating a set as a door prize for the Mooney Summit in Oct?

[Marauder]

1 hour ago, pmccand said: The standard yellow roll up foams have low frequency noise attenuation of about 25dB at 125Hz , but there are better (softer) foams available that attenuate in the 30+dB range.  (Btw, we have these softer foamies available) These softer foams are more in line with the latest quieting capabilities of the mega $AMU ANR headsets in the prop frequency range. 

Thanks for the information Phil. Which foams are you referring to? Were these included with the Halo or something new that you offer?

I switched over to his new softer foam version. Definitely better than the old yellow ones.

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[Raptor05121]

On 11/6/2015, 10:16:22, 201er said:

 ....so I got stuck having to use the Bose...

Oh, the humanity!