[Dexter Morgan]

Interesting, according to the HeadWize website:

"Whether closed-ear or in-ear headphones are used, an audiologist can measure the SPLs from inside a performer's ears with the help of a tiny probe to determine safe listening levels."

Has anyone tried this? BTW, that HeadWize webpage is a great resource, thanks to whomever posted the link.

 

[MusicallySilent]

Yea.... I just got my Marshmallows and used them over a trip that was 5 hours in a car.... I always had them relatively low... I think... I put my ipods max level at like 45% so I don't accidentally go over that and I could always hear my family members talking and road noise along with some music the car was playing (bass notes)

Would that be fine for my ears or might that be damaging?

 

[luckybaer]

Quote:

Originally Posted by Azure /img/forum/go_quote.gif Uh...so what if you only listen to music ~30 minutes or so a day? Then it's not dangerous to listen at ~95 dB?

I don't think that's the way it works, is it?

 

[msweeney]

Do you folks not own speakers? If you do and are as serious about sound quality through speakers as you are with your headphones then I am surprised so many of you don't own SPL meters. I don't know how else you would calibrate to reference levels. BTW, a lot of good info on this whole topic can be found over at AVSforum.

 

[Brian_the_King]

Pain is not a good way to measure hearing damage. I haven't read every post in this thread, so pardon if someone has brought this up, but hearing damage occurs before you feel any pain.

 

[ADD]

Quote:

Originally Posted by Funk-O-Meter /img/forum/go_quote.gif It doesn't work like that. It's an exponential thing. 104db is actually almost twice as loud as 102db.

I have noticed there is a lot of confusion on these forums about relative dB readings as well as how that relates to amplifier power ouputs. In the case above, 104 dB is not twice as loud as 102 dB - it is, infact just a fairly modest (but still quite noticeable) increase in loudness.

To have a perceived doubling of perceived loudness above 102 dB, the reading would become 112 dB - the scale is consistent in respect of the fact that each 10 dB increase is perceived as a doubling of loudness.

In respect of power outputs (since that has been mentioned in this thread as well) it takes a ten-fold power increase to produce a 10 dB increase in SPL. For example, if an IEM is rated at 110 dB for 1 milliwatt of power, then the device would produce 120 dB at a constant 10 milliwatts of power and 130 dB at a constant 100 milliwatts of power.

To produce an increase of 3 dB in SPL requires a doubling of power output. Using the same example above, the device would produce 113 dB at a constant 2 milliwatts power, 116 dB at a constant 4 milliwatts of power and 119 dB at a constant 8 milliwatts of power.

It's pretty obvious then that if one has a typical modern playback unit that puts out, say 20 milliwatts channel and sensitive IEMs rated at, perhaps 119 dB / milliwatt, then the SPLs reaching the eardrum can be catastrophic. In this example, were the source program to be normalised at a constant 1 dB below the 0 dB digital clipping threshold, then the maximum SPL would be 131 dB into each ear.

As for my own listening, I cannot measure because I use Westone UM2 monitors. I only listen to classical music, so I guess my hearing has the benefit of many quiet passages. However I estimate that I listen perhaps 3 - 5 dB below real life concert levels. I also limit my listening to no more than 45 minutes per day. To put that in perspective, I can neither mow my lawn nor vacuum my floor without using hearing protection - it is all just far too loud for me otherwise. I actually attended concerts regularly in years gone by, however in the last year I subscribed I was placed about 12 rows from the front. This proved too loud for me whenever the program material was something like a 20th Century or late romatic period symphony. I cancelled the subscription when I could not get a seat placement further back in the hall!

I actually suffer from tinnitus (ringing in the ears), but I did not get it from listening to a portable player. It resulted from both a respiratory illness and an allergic reaction to an antibiotic medication. In an audiogram test I had a month ago, my hearing was described by both the audiologist and my ENT doctor as "not only normal, but perfect". Lsitening to music through IEMs is - ironically - the only thing that relieves my tinnitus!

I think the type of program material and the quality with which it is recorded can have a lot to do with hearing fatique and possible damage. I always find that the closer the listening experience is to real life, the less fatiguing it is. For example, if I listen to old recordings made in the 1960s, they are quite fatiguing - often because the frequency response jumps around all over the place, there is a lot of mid-range harshness and not-so-pleasant analogue distortion. However, I am now buying those binaural recordings released by the Milwaukee Synphony Orchestra and they are the complete opposite experience. It's the closest I have ever gotten to "being there" at a live performance and I can listen at near-realistic concert levels wth absolutely zero fatigue and a perfectly relaxed set of ears when the UM2 monitors come out.

 

[ADD]

Quote:

Originally Posted by Frostychrist /img/forum/go_quote.gif I read that the Ipod's max volume is at 130db. If you play at half volume that would be 65db. But, As we all know, Different headphones player louder or softer at different volumes. I was thinking that if you could figure out what the highest level Db your headphones and player are playing at you should be able to adjust that with know problem. Anyone have any ideas on how to figure that out I would be curious?

That would be extremely difficult unless all the figures matched the printed specs perfectly. For example, the output of a player in mW is usually given into a specific impedance. So if you are using 27 ohm headphones and the specs were given at 32 or 16 ohms, then there is another thing to factor in. And even that would be too difficult, because one can't assume that a tiny portable player can produce a "perfect" voltage and current (and therefore the all important wattage) at all given parts of the frequency spectrum at all loudness levels. Add to that the fact that the volume controls on these devices are never linear in nature and any results could be quite misleading.

 

[matthewstevons]

Thanks for the info ADD! That cleared some stuff up for me. I thought I'd better post a "thanks" since that clearly took more than 30 seconds to write up.

 

[amphead]

Take this simple test to see if your hearing has been damaged.
Get a hand mirror, and a small flashlight.
Go to your bathroom mirror.
Turn the hand mirror until you can see the ear canal of your right ear.
Carefully shine the flashlight into your left ear.
If you can see light coming from your right ear canal, then you have hearing damage.

 

[Azure]

Quote:

Originally Posted by luckybaer /img/forum/go_quote.gif I don't think that's the way it works, is it?

I didn't think so, but does anybody have confirmation/explanation? Judging by the chart, it would seem that it wouldn't be too harmful, if at all...

 

[zyxwvutsr]

with classical music, I adjust the volume to such a point where the quietest parts of the track is just barely audible.
this method doesn't work well with tracks lacking in dynamic range as the overall sound level is too low.

 

[riceboy]

After reading a couple of threads about your hearing on Head-fi I decided to invest in a SPL meter (not the digital one, but either should be fine). I felt keeping my ears in good shape is important, since my hobby depends on it. After doing the cardboard mod with the SPL meter I was surprised to find I was listening around 75 - 80 dBs. I've been trying to listen around 70 - 75 dB now since I can measure it with my SPL. Not sure what most peeps have measured in, but I would be interested to know. IMHO, I feel that the SPL meter was the best investment/purchase I made since joining the forums and the RS1 and MAD Purist - HD2 is a definite second.

 

[JSTpt1022]

Thank you to ADD for the well written post. This is some of the most often misunderstood information on head-fi.

 

[ADD]

I've been trying to figure out a rough way to establish whether IEM volumes are damaging or not. I did notice that someone mentioned an audioloigist might be able to do this with some sort of probe, however I just wonder how effective that would be, since as soon as the integral seal between the IEM and ear canal is even slightly compromised, the readings can become extremely skewed, especially at lower frequencies (I assume the probe has to go into the ear canal).

Anyway, the rough way I figured what mine are doing is outlined below. In order to do this I had to know the power output of my player into my headphones and the headphones sensitivity. I also need to use digital processing software to adjust the volume on a number of test tracks by a specific number of decibels and to be able to know the precise RMS and peak dB readings in those adjusted files relative to the 0 dB clipping threshold.

So the raw figures I have to begin with: My Westone UM2 headphones are rated at 119 dB for every milliwatt of input power. My portable player puts out 18 milliwatts per chanel into 16 ohms and approximately 10 milliwatts per channel into the 27 ohm impedance of the Westones. That translates to each ear receiving 129 dB SPL were I to listen to a track recorded at a constant 0 dB (the digital level immediately below which digital clipping occurs) with the volume on the player maximised.

Of course, I don't listen to the player at maximum volume and the tracks I listen to are recorded nowhere near the 0 dB reference level. I listen to classical music and typically there is some 20 dB difference between peak and RMS volume, with many quiet passages being typically 50 - 60 dB below peak.

So I took a number of test tracks which I listen to and know extremely well. I then digitally edited them so as to reduce RMS output by very specific amounts. I created a number of versions that were processed at various levels between -30 and -15 dB below the original RMS levels. I then played these digitally altered versions back in my player with the volume control set at absolute maximum (being cautious of course, since I did not know how loud they were going to end up being - the versions below -18 dB I did not turn up to maximum because they had already exceed my normal listening level).

The aim of this was to establish how much I needed to digitally attentuate a track until it played at the precise same volume with my player set to maximum as it did when the player was set to my normal listening level. This was effectively a simple A - B comparison. I played the unaltered tracks at my normal listening level and the altered tracks at maximum volume until I achieved a perfect perceived match in volume between the two. I would select each "altered" track one at a time until I found the "perfect" amount of attentuation.

The outcome of this test was that I had to digitally reduce the volume of my tracks by an average of 17.8 dB in order to achieve exactly the same volumes as I did with normal listening.

The nest step in the process was to determine the average peak and RMS outputs of the tracks reduced by 17.8 dB. To do this, I used the "statistics" function in my Acoustica editing suite. After crunching all the figures, the RMS output of the altered tracks was 42.37 dB below the 0 dB reference level. Peaks were at 22 dB below the 0 dB reference.

It was then some simple calculations to determine to SPLs reaching my ears. I know that at maximum volume with a 0 dB signal, I am theoretically getting 129 dB at each ear. Taking the above mentioned figures from that total, I get approximately 86 dB RMS listening SPL and 107 dB at peaks.

It should be noted in my case that most of the program material I listen to is at the RMS figure or even lower. The peaks are very few and far between. You could look at a digital wav file and see a couple of them every ten minutes or so, each lasting a few milliseconds.

Nevertheless, these figures still came as a surprise to me, since I had always perceived I was listening at lower levels than that. So I think in my case I could do well to reduce my listening volume by perhaps a few decibels, even though I maybe only spend an hour per day listening.

Of course, the above excercise is a rough calculation and unfortunately relies as a starting point upon on the accuracy of theoretical specs. Still, I wouldn't be surprised if the 86 dB - 87 dB average figure I came up with was pretty close. Nevertheless, I only offer the above experiment as a personal case study which has no relevance to other people's situations.

I have come to the conclusion that the safest way to look after one's ears is to use headphones with which an accurate SPL can be taken when they are actually being used. I do not believe that achieving this with IEMs is possible unless an elaborate "dummy head" is used that mimicks aspects of your own oto-biology. Nevertheless, if I feel that my own results have some merit, they suggest that I was listening around 3 dB louder than I had always thought I was. That said, the volumes I choose to get out of my Westones still don't approach the sound levels I used to get at my orchestral subscription concert from row 12 in the concert hall (I cancelled the subscription simply because the music was too loud). I wish I had had a meter with me at those concerts to see how loud the really were!). I read many years ago that orchestras were supposed to peak out at 104 dB. Either that figure doesn't take into account the Sydney Symphony at full throttle with a Shostakovich symphony, or I'm not pushing my Westones as loud as I have just calculated.

 

[Darkestred]

damn to me a vacuum and lawn mower sound pretty identical. I know for sure i dont listen to my music louder than a vacuum and even then i find that loud.