What is Your Signal to Room Noise?

[esldude]

It is worth remembering noise is heavily weighted to the low end where we don't have sensitive hearing.  In rooms it usually has a profile somewhere between pink and brown noise. So in rooms I've measured in relatively though not unusually quiet conditions, the noise level around where our ears are most sensitive (3-5 khz) in a band similar to what our ear parses things up you'll get 10 or 15 dbSPL.  As we can hear into noise at least 10 db (maybe even 15 db) that means you in some portion of your hearing have a dynamic range with the lower end near 0 dbSPL.  So with 70 db SPL listening, you might have near 60 to 70 db effective dynamic range you'll hear.  Your hearing is most resolving around 70-75 db SPL.  

 

I once put up some test files with music and noise mixed in at different levels asking how much noise had to go down to become inaudible.  The general answers I received were around that -65-75 db range.  I'd think most people were comfortably listening at 70-to no more than 80 db SPL. So that all fits and makes sense.  

 

The broadband SNR might measure at only 35 to 40 db, but effectively it is more than that.  

[esldude]

Research by Dolby labs decided in a large room, for movies that 83 db SPL from one channel using pink noise was reference level.  It provided good headroom for louder peaks, and didn't over power people in most movies.  (I have to wonder about some special effects extravaganza's at those levels).  Bob Katz felt as music was a more constant volume than movies with dialog etc. 77 db made sense.  He suggested mastering people set this as reference level for their mastering work.  Smaller rooms which would apply to most of us would reduce it a bit more at least  3db.  For large orchestra works or some acoustic music turning up just a little makes sense.  

 

In any case an average level in the mid 70's provides headroom for peak loudness, and doesn't harm or tire out our hearing.  Now if you are playing heavy metal or rap and want concert levels this might not do.   Otherwise most people are listening in a good zone in the mid 70 db levels I think. 

[esldude]

20 minutes ago, PeterSt said:

 

This is actually what made me respond the way I did (which was not in a bragging fashion at all). This seems so far from reality that I can't comprehend.

Of course - I can envision people listen to music like this on Sunday mornings in a nice sunny corner of a room with a newspaper, some very faint background little music. But to say that if it would be louder than 70dB (which would be dish washer level) it would be jamming to the ears ... ?

Maybe your SPL meter is kaput ? or mine. Haha.

 

Now I'm not really sure what the message is or should be. I suppose the subject is something like: the lower the ambient noise level, the lower the music volume can be, because all is relative to the base noise and we must (try to) be well above that. This is also what I see a bit in esldude's/Dennis his post. But will it really work like that ? Thus, supposed my ambient noise would be a constant 50dBSPL for some reason, could I suddenly bear 100dBSPL easily ? seems hard to imagine. Still, all would be related to our - or the dynamic range we perceive. This makes it an interesting subject.

 

For me too the dynamic range "we" can perceive is something like 70dB maximum. This does not mean that we can utilize it, never mind we can also hear into the noise. Thus, it is hard for me to imagine that we can utilize that 70dB of range when music plays at 70dBSPL and we would be able to hear right into the noise up to 0dBSPL. Or ?

The other way around ... if my ambient noise would be 38dBSPL, would I be able to bear 108 dBSPL ? well, "bear" maybe yes, but would it be required to perceive everything which is in there ?

Or would 90dBSPL be OK because I can hear 18dB into my 38dB ambient noise ?

 

Yes, interesting.

 

I guess this is besides the hobby in a hobby of some (like me) who are only satisfied with something like concert levels. I mean, if I listen to Smoke on The Water from Made in Japan, I want to see that stage from the cover. This does not work on dish washer levels. At least not for me. Never mind I could hear all what's in there (say the full 70dB of dynamic range).

Well that mid-70 db range is average level, and you'd expect music if well recorded to have 20-25 db peaks above that at times.  Smoke on the Water from Made in Japan.  Yeah, good stuff, and I'd turn it up myself.  You can't listen like that for hours if you are going to keep hearing well. 

 

And yes, your ear filters to roughly a 1/5 octave wide area in the most sensitive region.  Looked at that way or with an SPL meter having an ERB setting you will get noise levels over that range of 10-15 db SPL.  You can try it yourself.  Play a quiet 3 khz tone and see where it disappears.  It won't have to be 40 db SPL for you to clearly hear it.  

 

 

[esldude]

Probably most of the noise is at a low frequency.  You can get RTA apps that will give a readout by octaves or less.  Of course most phone microphones drop off below 200 hz.