DbA Sound levels for youth gig night

[Matt Riley]

Hi guys, I've got to discuss the db levels for a new youth event we're staging. It will be for kids aged 13-16 and will mainly consist of live band nights. There will also be some club nights. If any of you guys run events like this, especially if you work in churches, it would be great to hear what you average at.

 

The meter is a £33 quid one from CPC. I'll refrain from commenting on the idea of enforcing db levels in this fashion with this kit, but hey-ho, I don't make the rules - I just wanted to enter the 'discussion' with a spread of real world numbers of what successful events are running so I don't end up being subject to uninformed arbitrarily picked numbers.

 

Cheers,

 

Matt

[BlueShift]

Well for starters, I'd have a look at what the HSE deems as safe/unsafe dosages. Hearing damage is about exposure over time in these kind of scenarios.

 

Secondly, your local council may have something to say about levels based on surrounding residents so you will need to check that out too.

[smalljoshua]

(This post has been made to reflect paid work I have done in youth centres and with reference to official consultation meetings about matters including Sound Levels)

 

For when I'm mixing youth nights, I try to keep levels to between 97-100 dBA.

 

We came to this figure as the format that our nights are in are based around 30 Min sets followed by 15 Min changeovers with lower level playback. At 30 minutes, the safe listening level is 97 dBA before hearing damage is sustained (figures from Google so not too sure on accuracy). We also figured that the lower level playback in between sets would help to keep us in the safe area.

 

We've been running at this level twice a month for the last 10 months now and it's going well.

 

Josh

[paulears]

Don't forget that the limits are for the protection of the workers, not the audience, as they get more exposure by repeat application.

[Doug Siddons]

I would say that Josh is about right, although for the younger ones I would try to get it down to 95db. The main problem when dealing with this age group is that they don't know how to turn down and the backline very often drowns out front of house, drummers are especially prone to just going for it and drowning out everyone else. There is also the fact that the audience all too often complain its not loud enough when your trying to be consciencious but thats kids for you :blink:

[Matt Riley]

Well for starters, I'd have a look at what the HSE deems as safe/unsafe dosages. Hearing damage is about exposure over time in these kind of scenarios.

For this event, there's only 3 paid staff involved, and our maximum exposure to loud noise would be about 3 hrs a week including soundchecks. So pretty much we'd have to be running ridiculously loud to go over the weekly action levels from the HSE. Even so, we will be educating volunteers and staff as to the situation and issuing hearing protection.

Secondly, your local council may have something to say about levels based on surrounding residents so you will need to check that out too.

True story. I hate formula sound black boxes with red lights on which stop everyone's fun, so I'll keep a close eye on it. Thankfully the venue is very much out of the way though so I reckon we're going to have to try awfully hard to get the neighbours wound up!

 

SmallJoshua - your thoughts roughly mirror mine. I just wanted to try and get a wide consensus as to the levels these events ran so keep it coming guys.

 

Cheers guys,

 

Matt

p.s. as a related aside we're in a 450 seat venue and we've got 2 of the EM acoustics I-8 subs. Do you think that if I put a couple of ohm trs 218s with big amps on them or some b2s in then we would end up being able to run at a lower volume without losing atmosphere as a result of having much better bass to the system?

[Simon Lewis]

Where to start?

 

Purple Book suggests an event Leq of 107dB(A) for punters, but is effectively assuming large outdoor events, and puts guidance about limiting proximity to loudspeakers etc.

 

Many engineers will mix to ~95dB for comfortable rock'n'roll. Our inestimable friend Mark Payne has a little party trick where he pushes the rig to 95dB by ear, and then measures it. He's normally within 0.1dB ;-)

 

Good low frequency reproduction will (psychoacoustically) give a sense of increased loudness.

 

Although I'm sure that 13-16 year olds can blow their ear drums out by various means (from iPods to sharpened pencils) I believe there should be a duty of care from the organisers to the young people attending such events. Perhaps not such a problem with your age group, but I have considerable problems with church events that blast very young kids ears with hours of loud music and speech but won't give them the opportunity of going somewhere quieter when it's all too much, because of their "child protection" policy. Guaranteed temporary threshold shift, or a slight chance of meeting Mr. P Dophile. Work that one out...

 

With regards to Control of Noise at Work...

So pretty much we'd have to be running ridiculously loud to go over the weekly action levels from the HSE.

... not really :huh:

 

Well your working week is taken as a nominal 5 days, so if your employee exposure is 3 hours a week, and that exposure was 100dB(A) Leq, your daily noise dose would be 96dB and your weekly noise dose 89dB. Both calculations assume no exposure to other sounds above 85dB. Both of these exposure levels exceed the upper action level and the exposure limit value. So you are breaking the law, and your £30 meter can't measure C weighted peak to determine if you are complying with the peak limits set in the regulations.

 

Of course, CONAWR doesn't allow the issuing of hearing protection as the first line of control but demands a reduction of noise at source ;-) Pragmatically, you would use PPE, but let's be clear that moderately loud gigs are over the action levels in the 'new' legislation. Also, you'd want to prove that the PPE issued was fit for the task and had a suitable assumed protection value.

 

Working to 96dB for 3 hours exceeds the daily limit but is within the weekly limit.

 

Just my 2pence worth...

 

Simon

 

edit... by the way, despite what the spellcheck might say, it's dB(A)

[Ynot]

My personal opinion - as an old fart - and one I've expressed here before...

 

If a gig is so loud that personal hearing protection is deemed to be even an option then the gig is TOO DARNED LOUD!!!!

I will always maintain that (especially in enclosed spaces) high volumes are detrimental to aural health and in many cases rather unnecessary.

 

But as I say - that's my opinion.

[Bobbsy]

....although to put 95dB(A) into context:

 

A while back I did some very boring sound for a ballet show (just walk in music and an announce mic a couple of times--and some monitor wedges upstage where it's hard to hear the pit). The rest of the music was a classical orchestra in the pit, completely unamplified.

 

The local theatre has an SPL meter with a readout at the FOH position--and the un-amplified orchestra frequently got to 95dB(A) or a bit above.

 

To the ear, the orchestra was loud and full--but certainly not perceived as in any way TOO loud. It just goes to show how careful you have to be with your hearing.

 

Bob

[Ynot]

I vaguely recall some research being done some while ago that looked at the comparitive sound levels from a concentrated source such as a speaker stack as opposed to a 'broadband' source like a full orchestra.

 

Of course I can't find it again now, but I think the conclusions went the way of the actual SPL of the orchestra was less damaging at the same perceived level than the same level being fired out from a speaker set.

(And of course that the frequency spectrum was very different...)

[Simon Lewis]

Ynot,

 

I'd be interested to see such research - it doesn't seem to fit in with the usually accepted view of "noise exposure is noise exposure". In fact, around 20 years ago, it was accepted that the dynamic range limitations of a sound reinforcement system were such that damaging peak levels couldn't be reproduced faithfully and were therefore less damaging than the "real thing".

 

I've not explored that line of reasoning for a while, but modern sound systems may well have capability that can deliver sustained > 140dBC peak levels at the listener's ear.

 

One other thing to remember before we fall into the trap of seeing 85dB(A) as a "speed sign" rather than a limiting dose: the epidemiological studies carried out on noise exposure risk look at worker's lifetime exposure. The revised 85dB(A) upper action level is for the worker who is exposed at this level 8 hours a day, 5 days a week for 40 years. Now, I'm not for one moment suggesting we all go out and blast our ears because we have a 76000 hour 'budget' to use up, but would say that occasional loud(ish) concerts may not be too problematic. This is something that the HSE recognise in their guidance.

Of course, if the listener goes to loud events regularly, works in a noisy environment and uses his or her personal music player to drown out transport noise, then it's time to buy shares in a hearing aid company.

 

Simon

[Ynot]

It was quite some time ago, and to be honest I can't remember whether it was online or in a newspaper.

Have done some Googling but nothing so far.

 

Hmmm...

[Yorkie]

For this event, there's only 3 paid staff involved, and our maximum exposure to loud noise would be about 3 hrs a week including soundchecks.

Paid staff and volunteer workers must be treated the same with regard to exposure and protection though, how much they earn has nothing to do with it!

[john deans]

A few years ago I provided PA for a festival with very well managed noise policy. The level for my venue was 100dB averaged over one min I think A weghted, I was not on the noise monitoring team. This correlated quite well with my 30 oddd year old Eagle sound level meter propped on the top of the mixer bouncing around 100dB. However an over enthusiatic drummer could still cause problems, so did one bands engineer & manager who whould not stay witnin the limits :P

[Matt Riley]

With regards to Control of Noise at Work...

So pretty much we'd have to be running ridiculously loud to go over the weekly action levels from the HSE.

... not really :P

 

Well your working week is taken as a nominal 5 days, so if your employee exposure is 3 hours a week, and that exposure was 100dB(A) Leq, your daily noise dose would be 96dB and your weekly noise dose 89dB. Both calculations assume no exposure to other sounds above 85dB. Both of these exposure levels exceed the upper action level and the exposure limit value. So you are breaking the law, and your £30 meter can't measure C weighted peak to determine if you are complying with the peak limits set in the regulations.

 

 

Thanks for your input Simon,

 

My big question is re: Leq versus the reading the handheld puts out... I know that the last time I used a proper Leq metering solution, there was a big difference between the slow a-weighted reading from the cheap meter and the 2.5k calibrated on site system we had for measuring Leq over 30 mins (to the tune of about 10dB higher for the cheapie). Am I correct in thinking the weapon of choice from the HSE is LA8EQ (sp?) ie Leq a-weighted over 8 hours for the daily dose? Is there any rule of thumb between the two?

 

TBH, I don't have any serious concerns about the levels being bandied about for this event. I rarely push the rig over about 100dB(a) and generally mix around 95dB. I'm just trying to make sure that I'm arguing for a policy which is healthy but also pragmatic.

 

The (milkshake!) bar area will be in a different room to the main venue, and we'll be having breakout rooms for xbox and wii etc which should also help keep things under control.