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#21
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Jonathan Goodish wrote:
Your logic is flawed. Human hearing is most prone to noise-induced damage at higher frequencies, where ANR has no effect. In fact, in this regard many passive sets provide more protection. You may want to read: http://www.anrheadsets.com/tutorial101-2.asp for a primer on the different issues related to frequencies and damage. Granted, LS has a vested interest in selling ANR headsets, but the whole ANR tutorial seems to be well balanced and factual. There have been long-term studies done on hearing protection afforded by passive devices, which have been proven to significantly reduce the risk of hearing loss. Absolutely correct. Almost any hearing protection is better than none. .... While I'm not suggesting that ANR devices are worse, there is no data to suggest that they're better. Yes, there is - see the above reference. -- Marc J. Zeitlin http://www.cozybuilders.org/ Copyright (c) 2006 |
#22
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On Thu, 31 Aug 2006 21:19:11 -0400, Roger
wrote: On Mon, 28 Aug 2006 09:18:09 +0200, Thomas Borchert wrote: Skym, How well do the ANR sets let me hear a little engine sound for peace of mind? Very. It's a total non-issue, a made-up argument by headset companies back when they didn't have an ANR model in their line-up, and by old cots not liking any change. The cost of a decent ANR set is significantly more than a very good passive set, Not really. In fact, not at all. Let's say a "very good passive set" is of the DC brand (I couldn't agree less, but...). That will set you back, what, 400, 500 bucks? For that, you'll be the proud owner of a Lightspeed 20XLc and have a 100-$-burger left. Go with a QFR XCc (or one of its pilot shop branded cousins) and you'll have two of those burgers left. "ANR is way more expensive" is just as much of a myth as "You can't hear the engine quitting with ANR". ANR is one of those areas where you can get a good set for about the same or less than a top of the line passive set or spend as much or more than you want. Try, then buy, but don't buy with out trying. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com I've been looking at headsets recently and came to the conclusion that the QFR XCC clone is a good compromise at $240. Compared to other ANR headsets it has some of the highest passive attenuation though only ~10db electronic. If the electronics fail it should still be very good. By the way Roger you mentioned in a previous post that 3db was half/double. I think you're still thinking of power not volts. I assume ANR refers to volts so think 6db = half/double, or am I getting rusty with all this? David |
#24
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Jonathan,
While I'm not suggesting that ANR devices are worse, there is no data to suggest that they're better. My personal experience counts for a lot to me. The difference in fatigue alone is dramatic. -- Thomas Borchert (EDDH) |
#25
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On Sat, 02 Sep 2006 14:25:05 -0400, "Roger (K8RI)"
wrote: On Sat, 02 Sep 2006 18:22:41 +0100, wrote: On Thu, 31 Aug 2006 21:19:11 -0400, Roger wrote: snip I've been looking at headsets recently and came to the conclusion that the QFR XCC clone is a good compromise at $240. Compared to other ANR headsets it has some of the highest passive attenuation though only ~10db electronic. If the electronics fail it should still be very good. By the way Roger you mentioned in a previous post that 3db was half/double. I think you're still thinking of power not volts. I assume ANR refers to volts so think 6db = half/double, or am I getting rusty with all this? Sound (and our hearing) is logarithmic so I'm pretty sure that the 3 db holds for sound as it does for power. David Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com Roger, now you've got me thinking:-) As you say it's logarithmic but if I'm not mistaken 10w to 100w =10dbw, 10v to 20v = 20dbv. I don't know how ANR is measured so I'm guessing dba but it looks like double = 6db. In an expample I found on the web and you compare say the Rifle & Threshold of Pain there's 6db difference. That would suggest headphones with say 26db passive attenuation would reduce the sound level by a factor of 40. If you use 3db then it would be a factor well over 500 which I think would be unrealistic. Source of sound Sound pressure Sound pressure level pascal dB re 20 µPa ============================================= Rifle being fired at 1 m: 200 Pa = 140 dB Threshold of pain: 100 Pa = 134 dB Hearing damage during short term effect: 20 Pa = approx. 120 dB Jet, 100 m distant: 6 – 200 Pa = 110 – 140 dB Jack hammer, 1 m distant / discotheque: 2 Pa approx. 100 dB Hearing damage during long-term effect: 6×10-1 Pa = approx. 90 dB David (GM3RFA) |
#26
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![]() Roger, now you've got me thinking:-) As you say it's logarithmic but if I'm not mistaken 10w to 100w =10dbw, 10v to 20v = 20dbv. I don't know how ANR is measured so I'm guessing dba but it looks like double = 6db. In an expample I found on the web and you compare say the Rifle & Threshold of Pain there's 6db difference. That would suggest headphones with say 26db passive attenuation would reduce the sound level by a factor of 40. If you use 3db then it would be a factor well over 500 which I think would be unrealistic. David (GM3RFA) Oops!, that should have beeb a factor of 20 not 40 David |
#27
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On Sat, 02 Sep 2006 20:50:46 +0100, wrote:
On Sat, 02 Sep 2006 14:25:05 -0400, "Roger (K8RI)" wrote: On Sat, 02 Sep 2006 18:22:41 +0100, wrote: On Thu, 31 Aug 2006 21:19:11 -0400, Roger wrote: snip I've been looking at headsets recently and came to the conclusion that the QFR XCC clone is a good compromise at $240. Compared to other ANR headsets it has some of the highest passive attenuation though only ~10db electronic. If the electronics fail it should still be very good. By the way Roger you mentioned in a previous post that 3db was half/double. I think you're still thinking of power not volts. I assume ANR refers to volts so think 6db = half/double, or am I getting rusty with all this? Sound (and our hearing) is logarithmic so I'm pretty sure that the 3 db holds for sound as it does for power. David Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com Roger, now you've got me thinking:-) As you say it's logarithmic but if I'm not mistaken 10w to 100w =10dbw, 10v to 20v = 20dbv. I don't That is correct, but sound is analogous to power not volts. know how ANR is measured so I'm guessing dba but it looks like double = 6db. In an expample I found on the web and you compare say the Rifle & Threshold of Pain there's 6db difference. That would suggest headphones with say 26db passive attenuation would reduce the sound level by a factor of 40. If you use 3db then it would be a factor well over 500 which I think would be unrealistic. Source of sound Sound pressure Sound pressure level pascal dB re 20 µPa ============================================= Rifle being fired at 1 m: 200 Pa = 140 dB Threshold of pain: 100 Pa = 134 dB Hearing damage during short term effect: 20 Pa = approx. 120 dB Jet, 100 m distant: 6 – 200 Pa = 110 – 140 dB Jack hammer, 1 m distant / discotheque: 2 Pa approx. 100 dB Hearing damage during long-term effect: 6×10-1 Pa = approx. 90 dB When I had a two blade prop on the Deb is was measured at 93 db at a distance of one city block and full RPM. So you can see why the neighbors off the end of 18 complained when I'd go over at roughly 300 feet on climb out at full power. :-)) David (GM3RFA) Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com |
#28
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On Mon, 04 Sep 2006 05:14:25 -0400, Roger
wrote: On Sat, 02 Sep 2006 20:50:46 +0100, wrote: On Sat, 02 Sep 2006 14:25:05 -0400, "Roger (K8RI)" wrote: On Sat, 02 Sep 2006 18:22:41 +0100, wrote: On Thu, 31 Aug 2006 21:19:11 -0400, Roger wrote: snip I've been looking at headsets recently and came to the conclusion that the QFR XCC clone is a good compromise at $240. Compared to other ANR headsets it has some of the highest passive attenuation though only ~10db electronic. If the electronics fail it should still be very good. By the way Roger you mentioned in a previous post that 3db was half/double. I think you're still thinking of power not volts. I assume ANR refers to volts so think 6db = half/double, or am I getting rusty with all this? Sound (and our hearing) is logarithmic so I'm pretty sure that the 3 db holds for sound as it does for power. David Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com Roger, now you've got me thinking:-) As you say it's logarithmic but if I'm not mistaken 10w to 100w =10dbw, 10v to 20v = 20dbv. I don't That is correct, but sound is analogous to power not volts. know how ANR is measured so I'm guessing dba but it looks like double = 6db. In an expample I found on the web and you compare say the Rifle & Threshold of Pain there's 6db difference. That would suggest headphones with say 26db passive attenuation would reduce the sound level by a factor of 40. If you use 3db then it would be a factor well over 500 which I think would be unrealistic. Source of sound Sound pressure Sound pressure level pascal dB re 20 µPa ============================================= Rifle being fired at 1 m: 200 Pa = 140 dB Threshold of pain: 100 Pa = 134 dB Hearing damage during short term effect: 20 Pa = approx. 120 dB Jet, 100 m distant: 6 – 200 Pa = 110 – 140 dB Jack hammer, 1 m distant / discotheque: 2 Pa approx. 100 dB Hearing damage during long-term effect: 6×10-1 Pa = approx. 90 dB When I had a two blade prop on the Deb is was measured at 93 db at a distance of one city block and full RPM. So you can see why the neighbors off the end of 18 complained when I'd go over at roughly 300 feet on climb out at full power. :-)) David (GM3RFA) Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com I'm not qualified to comment further on this topic so will let it lie and await somebody better qualified to chip in. Ok on the Deb, it sounds much louder than the PA28 I fly. Perhaps you need some 'Stealth bomber paint' so they don't know who you are? David |
#29
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On Mon, 04 Sep 2006 10:57:37 +0100, wrote:
On Mon, 04 Sep 2006 05:14:25 -0400, Roger wrote: On Sat, 02 Sep 2006 20:50:46 +0100, wrote: On Sat, 02 Sep 2006 14:25:05 -0400, "Roger (K8RI)" wrote: On Sat, 02 Sep 2006 18:22:41 +0100, wrote: On Thu, 31 Aug 2006 21:19:11 -0400, Roger wrote: snip I've been looking at headsets recently and came to the conclusion that the QFR XCC clone is a good compromise at $240. Compared to other ANR headsets it has some of the highest passive attenuation though only ~10db electronic. If the electronics fail it should still be very good. By the way Roger you mentioned in a previous post that 3db was half/double. I think you're still thinking of power not volts. I assume ANR refers to volts so think 6db = half/double, or am I getting rusty with all this? Sound (and our hearing) is logarithmic so I'm pretty sure that the 3 db holds for sound as it does for power. David Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com Roger, now you've got me thinking:-) As you say it's logarithmic but if I'm not mistaken 10w to 100w =10dbw, 10v to 20v = 20dbv. I don't That is correct, but sound is analogous to power not volts. know how ANR is measured so I'm guessing dba but it looks like double = 6db. In an expample I found on the web and you compare say the Rifle & Threshold of Pain there's 6db difference. That would suggest headphones with say 26db passive attenuation would reduce the sound level by a factor of 40. If you use 3db then it would be a factor well over 500 which I think would be unrealistic. Source of sound Sound pressure Sound pressure level pascal dB re 20 µPa ============================================= Rifle being fired at 1 m: 200 Pa = 140 dB Threshold of pain: 100 Pa = 134 dB Hearing damage during short term effect: 20 Pa = approx. 120 dB Jet, 100 m distant: 6 – 200 Pa = 110 – 140 dB Jack hammer, 1 m distant / discotheque: 2 Pa approx. 100 dB Hearing damage during long-term effect: 6×10-1 Pa = approx. 90 dB When I had a two blade prop on the Deb is was measured at 93 db at a distance of one city block and full RPM. So you can see why the neighbors off the end of 18 complained when I'd go over at roughly 300 feet on climb out at full power. :-)) David (GM3RFA) Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com I'm not qualified to comment further on this topic so will let it lie and await somebody better qualified to chip in. Ok on the Deb, it sounds much louder than the PA28 I fly. Perhaps you need some 'Stealth bomber paint' so they don't know who you are? And unfortunately I have those great big numbers on the side. sigh One *hot* afternoon, the wind was out of the SSE and gusty. That meant even the high performance stuff was using 18. Unfortunately that same subdivision fought lengthening 18/36 so *everyone* was going over their houses at 200 to 300 feet. I made three takes offs and landings that afternoon. We had a pair of Navions, a 310, two 210s, a couple of Bonanzas, some 182s and I don't remember what else. It was a busy day at the airport and I have no doubt they were telling the truth when they said they couldn't even carry on a conversation when one of us went over. To the non flying we all sound alike and the one guy wrote down my N number. He said I went over every five minutes. I can't take off, fly the pattern, land, taxi back and take off again in less than twice that. Fortunately he lost sympathy and credibility when accusing one plane of doing all that when the pattern was full most of the afternoon. I wasn't one of those paint jobs that changes color depending on your angle to the viewer and sun. That way no two people will give the same story. :-)) When we took off, loaded to gross for the day and I could see the grass under the picnic table through the gaps in the top I told my passengers "I'll bet we hear about this one!":-)) Which reminds me. That subdivision just popped up. One day I was on final for 36 and some guys were putting up a tall TV antenna. I noticed it was gone the next day. I had the gear down and full flaps with lots of power when I went directly over the top of it. I'll bet it was a bit drafty on top of that tower. Apparently they didn't know they are not allowed to go above the tree line around there. Actually I think it may be less than that. If you ever visit 3BS and land using the VASIs on 36 you'll know what I mean. Take a look just south of the expressway. David Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com |
#30
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On Wed, 06 Sep 2006 03:39:17 -0400, Roger
wrote: - snip - I'm not qualified to comment further on this topic so will let it lie and await somebody better qualified to chip in. Ok on the Deb, it sounds much louder than the PA28 I fly. Perhaps you need some 'Stealth bomber paint' so they don't know who you are? And unfortunately I have those great big numbers on the side. sigh Foiled! One *hot* afternoon, the wind was out of the SSE and gusty. That meant even the high performance stuff was using 18. Unfortunately that same subdivision fought lengthening 18/36 so *everyone* was going over their houses at 200 to 300 feet. I made three takes offs and landings that afternoon. We had a pair of Navions, a 310, two 210s, a couple of Bonanzas, some 182s and I don't remember what else. Don't tell me the airfield was built first, then they built houses, then they complained of the noise :-( Would you believe in the UK a new resident in a farming area complained of early morning noise from a farmer's cockerels. What's more he went to court and won despite the farm having animals for many many years. Perhaps they should have supplied ANR headsets? It was a busy day at the airport and I have no doubt they were telling the truth when they said they couldn't even carry on a conversation when one of us went over. To the non flying we all sound alike and the one guy wrote down my N number. He said I went over every five minutes. I can't take off, fly the pattern, land, taxi back and take off again in less than twice that. Fortunately he lost sympathy and credibility when accusing one plane of doing all that when the pattern was full most of the afternoon. I wasn't one of those paint jobs that changes color depending on your angle to the viewer and sun. That way no two people will give the same story. :-)) Never heard of that but it sounds good. We have the lower half of the aircraft dark red and the half upper white. Hopefull so it looks dark against the sky and light against the ground. Doubt it makes as much difference as the strobes. When we took off, loaded to gross for the day and I could see the grass under the picnic table through the gaps in the top I told my passengers "I'll bet we hear about this one!":-)) Oops! Which reminds me. That subdivision just popped up. One day I was on final for 36 and some guys were putting up a tall TV antenna. I noticed it was gone the next day. I had the gear down and full flaps with lots of power when I went directly over the top of it. I'll bet it was a bit drafty on top of that tower. Apparently they didn't know they are not allowed to go above the tree line around there. Actually I think it may be less than that. Last time I read my amateur licence I think it said antenna maximum of 50 ft within about half or 1 mile of an aerodrome in UK. I think anything else like kites are 200ft??? With low flying Military aircraft authorised to 200ft and some 50ft that could be a problem. If you ever visit 3BS and land using the VASIs on 36 you'll know what I mean. Take a look just south of the expressway. Doesn't look too bad using Google Earth but I guess flying gives a different perspective. David Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com David |
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