[wolfen68]

OK....with all this talk of hearing damage, I evaluated my listening rig to see where the appropriate safe listening levels were compared to what I usually listen to.

I brought a Quest Micro 15 Noise Dosimeter home from work that we typically use for noise level measurement in the workplace. I cut a cardboard form and mounted the probe exactly in the middle of the driver of my HF-1's (which should be similar impedence and output of any other Grado). I used my H140 line output and X5 head out (volume at max for both, their max output is virtually identical) to my SR-71.

I do not evaluate or adjust the gain on any of my mp3 tracks. Therefore, to provide a potential range, I picked a "hot" mp3 I was aware of in my collection and also another with a low gain. I ran the songs and took measurements in direct read mode.

Peaks at each setting are provided below:

High gain song...
@ 9 o'clock = 79 decibels
@ 10 o'clock = 87 decibels
@ 11 o'clock = 90 decibels
@ 12 o'clock = 96 decibels

Low gain song...
@ 9 o'clock = 63 decibels
@ 11 o'clock = 75 decibels
@ 12 o'clock = 84 decibels

Going back and forth, the H140 and X5 signals always yielded results within two decibels of each other.

Ultimately, the SR-71 was safe with every mp3 I tried up to the 9 o'clock volume position, but turning the dial even a little more flirted in the undesirable 85 decibel realm. That is only an allowable 1/4 turn of the volume dial!

I typically listen at 8-9 o'clock (less than 80 decibels), so these results gave me some confidence that I'm in the ballpark.

These results will vary with different equipment, but my rig is a very typical head-fi configuration, so I hope this helps someone else. Be safe.

EDIT: This was with regular bowls.

 

[dux]

Thanks for the information. I felt bad that no one had posted, but I'm sure a lot of us have read your post - there's just not too many people out there with the proper measuring equipment to compare notes!

Have you ever done a test with in-the-ear cans? (Yeah, what a visual!)

 

[warpdriver]

I was playing around with my Radioshack SPL meter with my loudspeakers, and I was actually surprised how loud 85dBA sounded. I picked a volume level on my receiver which I thought was quite loud and only very occasional it hit the 85dBA level. At least that gives me some confidence that I haven't been completely abusing my ears up till now.

It's nice to know that it's not *too* easy to exceed safe listening levels. With IEM's, it's much easier to stay within the bounds.

 

[Febs]

Quote:

Originally Posted by wolfen68 I brought a Quest Micro 15 Noise Dosimeter home from work that we typically use for noise level measurement in the workplace.

Very interesting measurements. Does the dosimeter allow you to measure a time weighted average?

 

[wolfen68]

Quote:

Originally Posted by Febs Very interesting measurements. Does the dosimeter allow you to measure a time weighted average?

Yes it does....but to be truly conservative, I just recorded the real time peak level I experienced at each pot setting of the amp.

As you probably know, a TWA would have yielded a lower result over time than I reported. The benefit of how I did it (for me) is that I now have absolute confidence that at a 9 o'clock setting or less, I will not be exposed to a 85 db or greater peak at any time.

To Warpdriver....85 db is actually louder than I thought as well. I think most people would be satisfied listening in the 75-80 db range. Other than waiting for negative symptoms, the trick is to train yourself to recognize the proper sound levels, or correlate your rig's output level to a pot setting as I have.

dux...I could not think of any reasonable way to get measurements off of my IEM's. The bores are too small for the probe to be effective. My "9 0'clock rule" will not work with them as they are far more sensitive.

 

[Medikit]

Thanks for posting this, Hearing loss amongst civilians has been on the rise in the united states since the introduction of the walkman

 

[Jam_Master_J]

Using a dB meter on both my headphone and speaker rigs surprised me at how loud 85 dB is. I'd say I've only exceeded 85dB for perhaps 2 or 3 times this month and only for quick dynamic bursts.

I aim for an average volume of about 70dB.

 

[aaroncort]

I think getting of of those do-dads for every head-fi party is a must. I think that it should be passed around so everybody knows what level they are listening at. I for one used to listen too loudly and have developed a very mild case of tinitus. I can only hear it at night and its about the same level as the sound of blood rushing in my ear.

 

[wolfen68]

Quote:

Originally Posted by aaroncort I think getting of of those do-dads for every head-fi party is a must. I think that it should be passed around so everybody knows what level they are listening at.

I promise I'll bring a couple of units and some cardboard to the next Head-fi meet I go to

 

[sclamb]

Interestng. I received my Radio Shack digital sound meter today and immediately cut a hole in some card, placed the measuring neck through it and pressed it against the earpad of my O2s to take a sound level reading. I was surpised that 80dB is actually a lot louder than the level that I was normally listening, which was nearer 65-70dB. As some have said earlier in this thread, I am surprised at how loud 80-85dB actually is.

Simon

 

[ironmics]

The reason why you may have been surprised at how loud 85 db is probably because you've heard it measure right next to a speaker. Power intensity levels drop off A LOT depending on how far away you are. 1 meter away is 4 times louder than 2 metters away which means if you're two meters away it's actually 79 db at your ear, 3 meters away drops down to around 75 or so dbs.

 

[XxATOLxX]

Cool. I'm only listening at 79db....

Does the SR-71 start at 6 o'clock by the way?

 

[sclamb]

Quote:

Originally Posted by ironmics The reason why you may have been surprised at how loud 85 db is probably because you've heard it measure right next to a speaker. Power intensity levels drop off A LOT depending on how far away you are. 1 meter away is 4 times louder than 2 metters away which means if you're two meters away it's actually 79 db at your ear, 3 meters away drops down to around 75 or so dbs.

I was measuring the sound inside the cup of my headphones, which is why I was surprised at how loud 85dB is. I always thought I might be listening at too loud a level, but it seems I am well into the safety zone.

Simon

 

[aaroncort]

Quote:

Originally Posted by XxATOLxX Cool. I'm only listening at 79db.... Does the SR-71 start at 6 o'clock by the way?

the sr-71 starts at 8 oclock

 

[wolfen68]

Quote:

Originally Posted by aaroncort the sr-71 starts at 8 oclock

My SR-71 starts @ 7 o'clock.

By stating 9 o'clock earlier, I meant the 3rd line up the volume scale. This would be the same as exact West on a compass.

Also, anybody doing this with their own equipment, make sure the probe is the same distance from the driver as your ear drum would be, and simulate the same closed environment of the cup just like you were wearing the headphones. This was the purpose of the cardboard (first suggested by forum member MD1032).