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Discussion Starter · #1 · (Edited)
If I entered this post in a wrong forum, I do apologize. In that case just move or delete it.

This is a question for JohnM I think.

This covers BOTH outside as inside music events (outdoors pop concerts/festivals - concert halls etc).

Circumstances: In France, UK and Switzerland are standards/regulations defining the maximum sound pressure levels the public/audience is allowed to be exposed to.
Other countries have no regulations for immission level in function of the audience itself, but have regulations protecting the environment or neighbors. The basic idea about such approach is that people are free to visit events with whatever sound levels, as long as such events do not disturb these people not choosing to make part of such things. Some countries will allow exceptions for such events by local community regulations, individual licenses (permissions), but limited in quantity and level.

In fact the way this should be controlled is Real Time.
But this should be measured with an integration time which can vary between 15' and 30'. In fact a running Leq of 15' (best adjustable) = about a moving average.
This data should be stored every 60 sec (or adjustable).
Further control is not only this progressing 15' Leq but also a second fast level meaning such regulations also limit max levels with a fast time integration.

An additional requirement is that such monitoring should happen (mostly) on a safe spot which is normally the mix console of the responsible audio engineer.
However, if one wants to protect people nothing guarantees that the loudest positions (closer to speakers, reflections, whatever) the audience is subjected to equals the level measured et the mix console.
:neener:If one should put a control mic between the audience itself that should likely only survive the first minute of such a festival.
Therefore before the actual event during sound setup and check with whatever source (pink noise, music to get a first impression) the difference between the loudest audience environment (averaging) position and the actual later monitor position should be stored as a correction curve, allowing to follow exactly the exposure level at the monitoring position.
It should be good that there is a graphical representation of this sound etc....

This is just a very rough first idea which can be more detailed and/or discussed.
My idea:
Averaging immission curves. Comparing these with the monitoring position, creating a correction curve.
Monitoring with adjustable integration time, but at least 2 simultaneously (even when only one is visible at the time). Data to be stored, allowing export based on adjustable time.
dBA weighting applied (formulas exist), possibly also other and or custom weightings.

The reason I'm triggered here is that the music world in Belgium has made a charter building in a control and limitation on themselves binding for all.
This is no small beer, in this sense that even the largest concert halls and events (as e.g. Werchter an outdoors event with 320,000 visiters, Pukkel Pop with 180,000 visitors, and so on) binding themselves to the terms of this Charter.
Wikipedia names already 195 Belgian outdoor festivals, this does not include smaller local events, discos and so on.

I'm indirectly involved now (as a music lover and retired acoustician but free of charge) in a possible adjustment of this Charter which, for now, represents more a declaration of intent rather than an acoustic accurate and usable document.

The background here is NOT commercial business or interest from my part, nor from the organizations behind this Charter, but protecting young people against noise-induced hearing loss and hearing damage (sensitivity loss, Tinnitus, Hyperacusis).
Simultaneously with this software side of the problem I'm also investigating the types and possibility to provide cheap but good and comfortable earplugs with do not rape the sound by their non-linearity in order to make them as easy an attractive as possible accessible on site on a price which is either free (covered by the ticket or just plain cost covering). Anyhow that still in investigation.

The reason I thought here on JohnM, is the respect I feel for his knowledge I felt in several topics, his existing freeware REW program which when extended can possibly reach a wider public and so on.

What's the gain? Not direct commercial affects, but indirect name recognition and the forum and site.
I can speak and write about freeware software, but from my background and involvement I can't and won't do commercial advertising.

This whole thing is based on social involvement. Indirect PR is a possible/likely result.
The effect of this Charter and everything surrounding it can have effect to other related stuff also across borders.

If it shouldn't be interesting here in the forum, any other suggestion is appreciated.

Warm regards
Eric Desart

Premium Member
6,711 Posts
Hi Eric,

Extensions to the REW SPL meter are on the list of things to do, including logging and plotting Leq over time. The only potential obstacles I can see are the time to add the features (so many features on the list to implement :)) and potential verification against calibrated implementations if the data is to be used to verify compliance against agreed limits, even if the limits are voluntary rather than regulatory.

3 Posts
Discussion Starter · #3 ·

Just to give you some idea:

This are the Swiss regulations. They cover laser beams and sound exposure.
If you understand German that should be helpful of course.
Th Belgian Charter will be a bit in line with these stipulations (with some adjustments).

I wanted to enter some related docs. But being a newbie I can't enter links the first 5 posts. (tried via CODE, etc. but didn't work)

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