[EagleWings]

  I think that there are two aspects of hearing protection that we should discuss. One being the pneumatic pressure and the other being prolonged exposure to loud noises. So, the way I understand it, the ADEL module helps to relieve the pneumatic pressure which that occurs when you enclose the ear canal with an IEM or headphones. These pneumatic pressures occurs when you enclose the ear, but not when you listen to music or are exposed to loud environments. I think that long exposure to this, can be harmful and I see general consensus in that people report not feeling, as much pressure when listening with their ADEL iems and also report the ear fatigue benefits.
 
On the other hand, there is still the risk of exposure to loud music. 

 
I agree with you on this. I recently bought a set of Earsonics Velvets. It pushed so much air when the beats dropped (sub-bass and bass notes), that it was literally pounding (pneumatic) my eardrums and it caused fatigue within minutes. From reading people’s impressions on the 1964 ADEL thread, ADEL Tech seems to address this issue and hence my interest in the 1964 ADEL IEMs.
 
However, with my limited knowledge on ear anatomy and hearing mechanism, I am not in a capacity to question if ADEL will protect the hearing from loud music. If it does protect, it is definitely an added benefit that is most welcome.

 

[maniac2003]

Good to see the reactions are sincere on this matter and just want to find out how and why ADEL works. I've watched a couple of video's meanwhile but I'm wondering: the ADEL unit is inside the earpiece. When is the pressure taken away. Right away when coming from the driver? or does the pressure enter ones ear and then bounces back where it's relieved by the ADEL unit?
I find the short YouTube video a bit difficult to understand as it differs from what the 64 Audio earpieces really look like, maybe it's just me 

 

[castleofargh]

  OK, I'll be the first to throw a stone. 
 
I have the A12's. They sound great. Fantastic bass and wide soundstage. I sold my Noble K10's after buying these.
 
I question the whole "Saves your hearing" thing. I'm not going to debate the sound pressure as I'm sure that has merit. However there is no debating that loud levels of noise can damage your hearing. That's a fact. So a loud dance club, rock concert, leaf blower, chainsaw, heavy equipment, etc, etc, do cause hearing damage with prolonged exposure and there is NO pressure on the eardrum.
 
As far as volume, I do not see the volume control on my Calyx M any lower using the A12's than when I used my K10's or my Roxanne's that I still have. So pressure may be relieved but there is still loud music being played directly into ones ear. So again, my argument is the music VOLUME can cause damage, and not just pressure.
 
Personally none of this bothers me as I did not but the A12's for the save my hearing feature. I bought them because they sound great. I'm just commenting that I don't believe the hype.
Ken

 
 
of course there is pressure on the eardrum when a loud sound is heard. the very fact that we're hearing a sound comes from the change in air pressure between the 2 sides of the eardrum. a single tone will increase then decrease the pressure in the ear canal at the frequency of said tone. so it's not one single constant pressure, but the louder the sound, the stronger the pressure at the ear(going up and down).
where you're right though, is that loud is bad, be it in a sealed ear or not. and longer exposure to loud sounds makes it worst. those are the 2 variables that really matter in the end.
 
the ADEL idea (and I don't endorse or refute it), is that when we use sealed IEMs, we can create an extra pressure from inserting the IEM. that in turn, would result in our ear's dampening protection to kick in sooner(or at a quieter volume than usual). and then, because our ear has reduced the sensitivity of the eardrum, we would in turn rise the volume level even more to compensate and get the "same" feeling of loudness. but here is the thing. in most cases, to get that feeling of loudness, we would reach a loudness level where the ear mechanism would kick in anyway.
so it looks like kind of a specific problem for people who would listen close to a certain level, but not really above it. or am I missing something? 
 
so my first reserve come with when our ear decides to increase the dampening.
second is about how it's uncomfortable when you get much pressure on the ear from inserting some IEMs in the ear. even with customs, I always try to unseal for a sec after I placed it in, moving the jaw, pulling the ear, moving the IEM around or all of the above at once. this as a way to reduce said pressure from the insertion. do I end up even, probably not exactly, but do I still get any benefit from such a valve? IDK. what are the added distortions from this system? IDK. is the valve having some kind of dynamic compression effect at certain frequencies? IDK.  do I like the tuning of the IEMs with that tech? IDK. ^_^
overall I would enjoy seeing a all lot of measurements done on that system to get a real idea of what is happening and at what price for the sound.
 
 
about

As far as volume, I do not see the volume control on my Calyx M any lower using the A12's than when I used my K10's or my Roxanne's that I still have.

your volume control tells about how many volts can go into the IEM. if you push it up, you send more volts, but different IEMs can have different sensitivities.
116db for 1mw and 15ohm(at 1khz and only there) for Rox, 116db for 1mw 16ohm for the A12. and not a clue about the K10, looking at the spec section on the website, it could just as well read "I ain't gonna tell you shiiit". at least the first 2 look like a close enough sensitivity for you to try and feel if something is obviously different. but again, measurements would do better given the differences in signature.

 

[Canyon Runner]

Ken, I can say that nobody is claiming that you can't blow out your ears while using a ADEL. It's not a "we solved hearing damage via IEMs" type thing. 

The examples you gave with the concert or leaf blower isn't pneumatic pressure related, they're acoustic. So they don't really apply to something that absorbs pneumatic pressures.

ADEL isn't a cure-all fix for things that cause hearing loss but it's an improvement for when you have something sealed in your ear.

The improvement is done by helping keep the body's acoustic reflex from triggering prematurely and starting the cycle of your ear numbing its sensitivity and you turning up the volume on your amp, again and again. Because that harmful pressure is being absorbed through ADEL, your body hasn't begun trying to block it out and become less sensitive. Therefore it stays able to listen properly and you don't need high volumes to overpower that response. This keeps you listening at a lower volume for expended time, rather than having you creep the volume up to make the music sound like it did before your reflex was triggered.

The acoustic reflex tightens a muscle in your ear and like any muscle, if it's tighten for prolonged period of time, or tightened & relaxed, again and again, it gets fatigued. 

If you want to do an easy test, you can cover the vent hole on your Auto module on your A12. Listen to music at your normal volume, see if you end up feeling any sort of fatigue. Now do it with tape off the vent hole, letting ADEL work. See if you're feeling the same by the time mark. 

ADEL is also helping by having lower volumes sound louder. This is done because ADEL is letting some of that sound, along with the pneumatic pressure escape your ear canal. Think 2 cups being filled up by a constant stream of water, one is sealed, one has a hole. The one with the hole is going to let some constantly escape. The faucet is pouring out the same amount of water into the cups, but the one with the hole isn't filling up as much. If you don’t have a seal with your IEM, that pressure and sound is escaping, but you get no bottom end. The ADEL membrane is super thin, allowing some of that pressure to pass through the membrane, while maintaining a seal. This is why there’s a difference between ADEL being there and just pulling the module out altogether.

 

[Canyon Runner]

  Good to see the reactions are sincere on this matter and just want to find out how and why ADEL works. I've watched a couple of video's meanwhile but I'm wondering: the ADEL unit is inside the earpiece. When is the pressure taken away. Right away when coming from the driver? or does the pressure enter ones ear and then bounces back where it's relieved by the ADEL unit?
I find the short YouTube video a bit difficult to understand as it differs from what the 64 Audio earpieces really look like, maybe it's just me 

ADEL has it's own bore within the IEM's snout, so when the IEM is sealed to your ear, ADELs bore is now apart of the ear canals space. Just like the tubes funneling sound in. Rather than putting sound or pressure into the ear canal, it's allowing it to be vented out of the ear canal. 

 

[ken6217]

Ken, I can say that nobody is claiming that you can't blow out your ears while using a ADEL. It's not a "we solved hearing damage via IEMs" type thing. 

The examples you gave with the concert or leaf blower isn't pneumatic pressure related, they're acoustic. So they don't really apply to something that absorbs pneumatic pressures.

ADEL isn't a cure-all fix for things that cause hearing loss but it's an improvement for when you have something sealed in your ear.

The improvement is done by helping keep the body's acoustic reflex from triggering prematurely and starting the cycle of your ear numbing its sensitivity and you turning up the volume on your amp, again and again. Because that harmful pressure is being absorbed through ADEL, your body hasn't begun trying to block it out and become less sensitive. Therefore it stays able to listen properly and you don't need high volumes to overpower that response. This keeps you listening at a lower volume for expended time, rather than having you creep the volume up to make the music sound like it did before your reflex was triggered.


The acoustic reflex tightens a muscle in your ear and like any muscle, if it's tighten for prolonged period of time, or tightened & relaxed, again and again, it gets fatigued. 

If you want to do an easy test, you can cover the vent hole on your Auto module on your A12. Listen to music at your normal volume, see if you end up feeling any sort of fatigue. Now do it with tape off the vent hole, letting ADEL work. See if you're feeling the same by the time mark. 

ADEL is also helping by having lower volumes sound louder. This is done because ADEL is letting some of that sound, along with the pneumatic pressure escape your ear canal. Think 2 cups being filled up by a constant stream of water, one is sealed, one has a hole. The one with the hole is going to let some constantly escape. The faucet is pouring out the same amount of water into the cups, but the one with the hole isn't filling up as much. If you don’t have a seal with your IEM, that pressure and sound is escaping, but you get no bottom end. The ADEL membrane is super thin, allowing some of that pressure to pass through the membrane, while maintaining a seal. This is why there’s a difference between ADEL being there and just pulling the module out altogether.

You won't convince me. I'm not even going for the sound pressure discussion. I'm keeping it simple. Playing my A12 sounds the same to me as any other IEM I have listened to in terms of loudness.

My comments regarding other things that produce loud volumes are relevant to my point. If you want to say that with the module there is less pressure and is less fatiguing, that very well may be the case. But to say that playing music with it is any different than other IEM's in terms of decibels in your ears is not fact.

I cannot play my DAP any lower than I did before and get the same sound quality as if playing it louder. IF there is any difference, then it is splitting hairs. And that's hairs that I can't hear.

As mentioned previously, they sound great. Maybe that's the ADEL module. However I don't see it (hear it) as producing less volume in my ears.

Anyway, this is how I view it after owning these for about 6 weeks.

 

[Brooko]

May as well chuck my 2c in - based on my own experience.  And Steve - I'll email you later today re the Spreecast - definitely interested, and if you want me to help front it, and we can fit around the time diffs, then I'm more than happy to do it.
 
I have permanent tinnitus - the result of prolonged exposure at a 4 hour concert in a very small venue with nowhere to escape to, and (stupidly) I took no hearing protection.  I had no experience of the venue, and didn't really want to go (not a Jimmy Barnes fan) - but felt obliged to because my wife was invited by her new boss at the time. At the end of 4 hours, my ears were ringing incredibly loud (didn't notice it at the time due to the "assault" of the music.  I couldn't hear anything for 2 days following.  The ringing eventually subsided.  Pretty much everything above 15 kHz is now gone for me - but the low level ringing is permanent.  You learn to live with it - but OMG I would love to hear simple silence again.
 
Since then (it happened about 15 years ago) I have constantly worried about making sure I look after what I have left.  When I'm listening to something with my wife or teenage kids (TV, radio etc) I need a louder output volume than they do - but all 3 of them have brilliant hearing - probably in the top 10-15%.  My wife and daughter can hear our cat walking on carpet - that sort of sensitivity. Makes me quite envious.
 
What surprised me though was going to a local Meet last year, and on my way around the room, at almost every amp, I needed to turn the volume down for a comfortable listening volume.  And there were some of the younger set who had open headphones sounding like speakers (worn).  So I think this highlights the differences.
 
Steve and c-of-a have already highlighted some of the tech behind the Adel modules. My understanding is that it releases pneumatic pressure so that the ears acoustic protection doesn't dampen the sound prematurely.  For a quieter listener like me, this is brilliant.  What I am constantly finding is that when I'm listening to the U6 I am more commonly turning the volume down over time - simply because I'm getting all the detail I need at much lower listening levels.  The isolation really helps too - even with the Adel module in place, I don't have to have it turned right up. As others have said too - I don;t get listening fatigue with the U6, and (for me) it doesn't cause my tinnitus to flare as much as other IEMs. With some - the noticeable ringing will increase - with Adel it doesn't.
 
So why does it work for me and not for others?  I'm pretty sure this is where the "normal listening volume" differences kick in. If you are a loud listener, the pneumatic pressure might be lessened a little, but will still probably trigger the acoustic dampening, you'll still continue to turn your music up, and you're not going to notice any difference.  If you fall into that category - I'd invite you to possibly try turning the music down for a day.  Get used to the new volume.  See if you can adapt successfully to allowing the Adel module to function as it should.  And you may just find that by doing it you will still get the same enjoyment, and more importantly (hopefully) you'll never have to experience (and live with daily) what has become my norm (constant sound).
 
YMMV - but worth trying I think.

 

[bavinck]

Honestly, buying a mojo has really helped me keep the volumes lower. Detail and dynamics are excellent at low volumes with the mojo, I don't feel the need to turn it up for enjoy!

 

[WCDchee]

eveb if you prevent the protective acoustic reflex from kicking in early, it shouldn't affect anything. Noise induced hearing loss occurs at 4khz in the middle ear, not the ear drum. As such, the reflex simply decreases eardrum compliance, resulting in a smaller amplitude of vibrations, and similarly, a smaller amplitude of vibrations reaching the inner ear. This actually causes you to hear things more softly.

Thus, when you hear Two things of equal volume, regardless of the input, it means the same amplitude of vibrations are reaching the inner ear, and as such trauma to the hair cells there would be the same.

This issue of pneumatic pressure, well whatever the effect on the eardrum, noise induced hearing loss is not caused by damage to the eardrum, hence my reservations to this.

 

[castleofargh]

 

Spoiler: Warning: Spoiler!

May as well chuck my 2c in - based on my own experience.  And Steve - I'll email you later today re the Spreecast - definitely interested, and if you want me to help front it, and we can fit around the time diffs, then I'm more than happy to do it.
 
I have permanent tinnitus - the result of prolonged exposure at a 4 hour concert in a very small venue with nowhere to escape to, and (stupidly) I took no hearing protection.  I had no experience of the venue, and didn't really want to go (not a Jimmy Barnes fan) - but felt obliged to because my wife was invited by her new boss at the time. At the end of 4 hours, my ears were ringing incredibly loud (didn't notice it at the time due to the "assault" of the music.  I couldn't hear anything for 2 days following.  The ringing eventually subsided.  Pretty much everything above 15 kHz is now gone for me - but the low level ringing is permanent.  You learn to live with it - but OMG I would love to hear simple silence again.
 
Since then (it happened about 15 years ago) I have constantly worried about making sure I look after what I have left.  When I'm listening to something with my wife or teenage kids (TV, radio etc) I need a louder output volume than they do - but all 3 of them have brilliant hearing - probably in the top 10-15%.  My wife and daughter can hear our cat walking on carpet - that sort of sensitivity. Makes me quite envious.
 
What surprised me though was going to a local Meet last year, and on my way around the room, at almost every amp, I needed to turn the volume down for a comfortable listening volume.  And there were some of the younger set who had open headphones sounding like speakers (worn).  So I think this highlights the differences.
 
Steve and c-of-a have already highlighted some of the tech behind the Adel modules. My understanding is that it releases pneumatic pressure so that the ears acoustic protection doesn't dampen the sound prematurely.  For a quieter listener like me, this is brilliant.  What I am constantly finding is that when I'm listening to the U6 I am more commonly turning the volume down over time - simply because I'm getting all the detail I need at much lower listening levels.  The isolation really helps too - even with the Adel module in place, I don't have to have it turned right up. As others have said too - I don;t get listening fatigue with the U6, and (for me) it doesn't cause my tinnitus to flare as much as other IEMs. With some - the noticeable ringing will increase - with Adel it doesn't.
 
So why does it work for me and not for others?  I'm pretty sure this is where the "normal listening volume" differences kick in. If you are a loud listener, the pneumatic pressure might be lessened a little, but will still probably trigger the acoustic dampening, you'll still continue to turn your music up, and you're not going to notice any difference.  If you fall into that category - I'd invite you to possibly try turning the music down for a day.  Get used to the new volume.  See if you can adapt successfully to allowing the Adel module to function as it should.  And you may just find that by doing it you will still get the same enjoyment, and more importantly (hopefully) you'll never have to experience (and live with daily) what has become my norm (constant sound).
 
YMMV - but worth trying I think.

 

very relevant comment about people's idea of normal listening levels!!!! I pretty much spent my time at meets lowering the volume. well meets are noisy places and people go for the louder is better and always hope to impress you with their gears, so I guess/hope for them, that it's the main reason why they almost all have the sound so loud.
but over time, I'm always one of the guys complaining the most about background hiss, or IEM having poor isolation. so I do still listen below your average guy(because trust me I'm no golden ear). as a result, other noises are the number one reason for me to end up rising the volume level.
and that's why I value crappy etymotic IEMs so much, they have mad isolation(while super small). even though they are the typical cases of IEMs that can lead to too much pressure in the ear. they need to be inserted pretty deep and the default triflange tips certainly don't help balancing the pressure inside the ear canal. reason why I use foam, that way not much pressure trouble. but that too isn't a magical solution with zero drawback, so maybe stuff like the ADEL membrane could be a good idea. again I'm the kind of guy who has to try the stuff extensively, or see a great deal of measurements to believe in any marketing explanation. so I reserve my love or hatred for when I'll know something ^_^.

 

[ken6217]

I had sent my A12's back for a refit and just recently gotten them back. I did some more listening to them today and then more after my previous posts to pay more attention.
 
First, let me get this out of the way.... These things sound unfreakinbelievable!! (Had a tough time with spellcheck for that one).
 
I found that in fact you can really listen to these for a long time without fatigue and at louder volumes without them being tiring at all. This would have to be the ADEL module. However since I am so accustomed to listening to loud music, I find that I am turing it up just as loud because it is not uncomfortable to do so. 
 
Maybe I should try listening at lower volumes for a couple of days to see if I get used to that.
 
Btw, I don't know if it is the module that is giving such as expansive soundstage, but these A12's are amazing in that aspect.
 
The bottom line though is that these really sound amazing. Did I say that already?
Ken

 

[tkteo]

This issue of pneumatic pressure, well whatever the effect on the eardrum, noise induced hearing loss is not caused by damage to the eardrum, hence my reservations to this.

Are you instead referring to damage to the "hair cells" in the inner ear?
http://www.asha.org/public/hearing/How-We-Hear/
http://www.hearingloss.org/content/types-causes-and-treatment

 

[WCDchee]

Are you instead referring to damage to the "hair cells" in the inner ear?
http://www.asha.org/public/hearing/How-We-Hear/
http://www.hearingloss.org/content/types-causes-and-treatment

Yup! That's exactly what I'm saying. Unless I am mistaken, Pneumatic pressure (whatever it is) on the eardrums is not a documented mode for hearing damage.

 

[Brooko]

But isn't the idea that the pneumatic pressure triggers the ears dampening mechanism (safety) to protect from the louder volumes?  As a result of it being triggered, we tend to turn the music up louder, thus over-riding the acoustic reflex, putting even louder levels into our ears, and causing further damage.
 
Stephen hasn't talked about damage from pneumatic pressure.  He's talked about releasing some of that pressure so that the dampening mechanism isn't triggered and then we don't keep turning the volume up.
 
Couple that with good isolation, and good tuning which means you can actually hear more detail at softer levels - and I'd call it a win.
 
In my personal case, I'm actually turning the volume down a little with the Adel U6.  There is no reason to be listening at very loud levels.
 
That's my understanding anyway.

 

[WCDchee]

But isn't the idea that the pneumatic pressure triggers the ears dampening mechanism (safety) to protect from the louder volumes?  As a result of it being triggered, we tend to turn the music up louder, thus over-riding the acoustic reflex, putting even louder levels into our ears, and causing further damage.

Stephen hasn't talked about damage from pneumatic pressure.  He's talked about releasing some of that pressure so that the dampening mechanism isn't triggered and then we don't keep turning the volume up.

Couple that with good isolation, and good tuning which means you can actually hear more detail at softer levels - and I'd call it a win.

In my personal case, I'm actually turning the volume down a little with the Adel U6.  There is no reason to be listening at very loud levels.

That's my understanding anyway.

My understanding is that the triggering of the reflex results in some damping of the sound, resulting in the transmitted vibrations to the inner ear to be of a smaller amplitude. If we overcome this by turning the volume up, then yes it increases the amplitude of the vibrations.

As such, if you compare two situations, one with the triggered reflex and one without, if the same volume is being played, the situation with the triggered reflex would actually have less vibrations reaching the inner ear resulting in less trauma to the hair cells. Subsequently if we turn the volume up to match the situation without the reflex triggered, such that we hear the same thing in both cases, ultimately, the same amplitude of vibrations reach the inner ear in both situations resulting in equal trauma to the inner ear.

Thus, assuming that we hear the same thing in both situations, while the actual volume played may be louder in the situation where the reflex is triggered, the fact that we hear the same loudness in both situations means that the triggering of the reflex adequately damps the excess vibrations to a safer level

One more thing to consider is this, ear pressures should equilibrate in a few minutes if the Eustachian tube is functioning well, completely negating the effect of the pressure build up too