File this one under 'mad science' if you like, but did you know that if you could crank the volume level at your next gig up to 165dB, your audience's hair would catch fire? Now there's one for Metallica fans! In fairness, you would need a bit more than the average PA system to achieve this sort of sound pressure level, which is thousands of times louder than the worst you'll suffer at a Rock concert - generally reckoned to peak at around 125dB. Why such a huge increase for so few dBs? That's just one of the pitfalls awaiting the unwary in the subject of noise pollution - something which, whether we like it or not, gigging musicians, DJs, sound engineers and, in particular, promoters and venue owners, are currently being forced to take seriously, as noise legislation becomes more strictly enforced across the UK .
There's nothing new about concerns over the level of sound generated by music - nor in the stories about famous musicians, DJs and engineers whose hearing has suffered permanent damage, due to exposure on stage and in the studio. You might think that what artists do to themselves is their business - and, assuming they know in advance what harm they could be doing, that's a perfectly reasonable point of view. But what about their audiences? OK, they volunteer, by paying to attend gigs and clubs, so maybe they know what they are letting themselves in for, too - though it's likely that few paying punters have even the vaguest idea what they could be doing to their hearing at an all-night 110dB rave. But what about those who work at the clubs and gigs? And what about the noise pollution that spills down the street to annoy the neighbours? It is in these two areas - potential harm caused to employees and noise problems caused to nearby residents - that the law has started to take a definite interest in - to the extent that clubs and pubs now face very real threats to their licenses unless they take effective steps to control noise levels. Which means that you, the DJ or musician playing there, are going to be affected too.
To make any sense of noise levels, the first thing you have to understand is that the units used for measuring noise, decibels, work in a logarithmic scale. This is why, though in our opening example, the 165dB level needed to ignite your audience, doesn't seem that much of an increase over the 125dB they were expecting, it is, in reality, a huge increase in intensity. In fact it takes just 3dB increase to double the noise level.
The RNID (the UK charity for people with deafness and hearing loss) gives some useful rough guidelines, which put things into perspective. It reckons that 20dB(A) is the level you'd experience in a quiet room at night. Incidentally, the 'A' refers to a filtering method, designed to represent human sensitivity to frequency. 70dB(A) would be typical of a busy city street, while 80dB(A) is shouting-level. Anything over 80, it claims, can damage your hearing and 85dB(A) is the level at which the law starts to get involved. As a sign of the ever-tightening grip of the Noise Nanny, this upper figure, under new EU regulations, has to be reduced to 80dB by 2006 - though a two year delay has been negotiated by various entertainment industry bodies, while they try to figure out how on earth this sort of legislation can be applied in an industry which is, essentially...well, noisy.
The legislation regarding noise at work stems from an EU directive, dating from 1986. Each EU country has implemented this in its own way - in the UK with Noise At Work legislation, dating from 1989. This opeartes on the generally accepted principle that (not unlike exposure to radioactivity) the damage done isn't solely by a one-off exposure, but also by a cumulative exposure to lower doses. Why it concerns us is because this legislation doesn't just apply to car factories and steel works - it applies every bit as much to the bar staff in a club. And as the noise level on a typical club dance floor can be 90dB or more (much more in some cases) then there is definite problem, which can land an employer in serious trouble. The law is unambiguous: if your staff are exposed to 85dB(A) you have to advise them that their hearing could be at risk, and provide hearing protection for their use. If the noise levels are above 90dB(A) then the employer not only has to provide hearing protection - he has to enforce its use. That you don't see much evidence of this in clubs, pubs and gig venues at present, doesn't mean a thing: increased enforcement is coming.
Though this doesn't, directly, affect you when you turn up at a gig to play on a freelance basis, it may increasingly mean that the promoter will insist that you use some kind of noise control equipment to ensure that he stays on the right side of the law. Whether you voluntarily choose to wear hearing protection is probably up to you (it's a fine legal point whether you'd qualify as an employee, though staff DJs certainly would) but you'd be nuts not to, given the risk to your own hearing - particularly if you are regularly exposed to high SPLs.
And what about the neighbours? This, increasingly, is another thorn in the flesh for venues. Although legislation covering the effects of noise pollution outside venues dates as far back as 1974, it is increasingly being applied across the UK - and in Scotland, the legislation is even more draconian - causing some real problems to promoters and club owners.
One of the leading manufacturers of the equipment you will increasingly (he hopes!) be finding in the venues you play is Tony Cockle, managing director of Formula Sound, and an acknowledged expert in this field. Formula Sound supplies two types of noise control apparatus - its AVC 2 Automatic Volume Control and the Sentry Mk II. On the face of it, an 'automatic volume control' - which acts like an invisible hand on the master fader - sounds like just the thing and, indeed, Formula Sound has apparently supplied a lot of these units, but this kind of device has its limitations. It works best in fixed installations with permanent sound systems and needs to be calibrated to suit the venue in question. The Sentry Mk II, on the other had, though it seems a more brutal solution, in that it simply turns off the juice, is the more suitable product for mobile systems.
Tony Cockle says the legislation that is increasingly being applied to venues is strict. For example, the way the dose is calculated can cause real problems. 'While the basic level of exposure is allowed for an eight hour day, above that, for every 3dB increase, the time comes down by half,' he says. 'So when you start getting up into the 90s, you can't be there very long and 90dB is not unusual for a club - in fact it's not unusual to see 110dB out of a sound system. Many smaller venues still haven't a clue how much noise their staff are exposed to, though the larger ones have mostly taken this on board.
'Then there's the noise pollution legislation. In effect this says that anybody living anywhere shouldn't be exposed to noise pollution. So if you're a nightclub in the middle of town and you've got flats upstairs, basically, if they can hear your sound system, all they have to do is complain and you've immediately got the Environmental Health Officer on your back - and his rules are very simple. If they can hear it, it's a nuisance. Which means that your building has to contain the noise.
'People often phone me and ask how much noise they can make and I can't tell them. Basically, I have to say go and stand on your neighbour's boundary and if you can hear your sound system, the chances are it's too loud, so turn it down till you can't hear it, then use a device that doesn't let it go any higher than that.'
All of which gets even more complicated when you consider that much of the enforcement is down to the discretion of the individual Environmental Health Officer and few (if any) of these are qualified acoustic engineers. 'EHOs, with the best will in the world, have a job to do,' says Tony Cockle. 'They've all been on courses, but very few of them know anything at all about sound systems. But the legislation is in place and it has to be dealt with. It's not recent legislation, either - but lately it has become more and more of an issue and it now is getting enforced.'
Mercifully, that legislation doesn't (yet) affect what happens on the dance floor. 'You can make as much racket there as you like, providing you can keep that noise way from your bar staff - which is easier said than done. But the numbers that people are bandying around now can be very worrying. I saw an article in which the one leading club was quoted as saying that their sound system is capable of developing 140dB - that's about as loud as a shotgun being let off about a yard from your ear. You wouldn't have to be exposed to that sort of level for very long before you'd be deaf.
'The thing we've all got to take on board is that we, as professionals in this business, have brought this on ourselves. We've played too loud for too long and you don't have to play at mind-blowing levels to produce something that's enjoyable. All the government is saying is that this situation has to stop - and we don't like it because we don't like being to do what to do, but it's self-inflicted.
'As for how you control it, that falls into two categories. If you've got an installed system, you can put a device on it which will stop the operators playing it any louder than you've decided - and that's our AVC2. The problem comes when people bring in their own equipment - for example when someone hires a village hall for a party or a gig. The only way to control noise there is to control the mains supply that is used to generate the noise, which is what the Sentry does. It tells you if you have crossed what has deemed to be the allowed level and then, if you don't do something about it, it turns you off. Kit has been around for years that does that, but the problem with some of the early equipment was that it used to switch back on automatically after a set period of time - and that's dangerous to equipment. In fact it led to bands refusing to play at venues where that sort of system was used. The Sentry won't do that - it has to be manually switched back on, so people have the chance to make their equipment safe beforehand.
'There is a bit of a tricky problem these days with computer-based kit which your readers ought to be aware of. The chances are it will be ok, but you might just have an issue if the power is suddenly turned off. So what we say to people is to supply a separate feed fused at very little current - say an amp or so. Then, if a band has computerised kit, run it from that feed, which isn't enough for the sound system, which alone is controlled by the Sentry.'
And if you happen to find yourself at a noise controlled venue with a laptop, or other computerised equipment (for example keyboards) that is advice worth bearing in mind.
If simply turning the power off seems a bit too crude, there is, Tony Cockle says, a more subtle system that can be added to the Sentry: the AT-1, an attenuated device with two ins and two outs. The user plugs the output of his mixer into the box, the output from that goes into his power amp and that attenuates the level to whatever level has been preordained. And if he doesn't plug in? Then the Sentry simply switches him off if he gets too loud. For the record, this is not expensive equipment - a complete system won't cost much more than £1,000 plus fitting.
As Tony Cockle suggests, the noise levels at some venues are pretty serious. Karen Baxter of the RNID says that an undercover survey the charity undertook last year in five different cities revealed quite disturbing levels, which were detailed in its report A Noise Hangover, which it published this year and promoted as part of campaign at this year's Glastonbury and other festivals. 'At the moment, there isn't any legislation that covers audiences, but the legislation does cover the DJs and bar staff if they are employees, so what we have been calling for as part of our campaign, is for venue owners to join a voluntary campaign whereby they don't play the music massively loud - though we accept that if you go to a nightclub you want to hear the music loud. What we really want to see is the level of volume in chill-out areas lowered to a maximum of 80dB as a base level, to give people's ears a rest. We also want earplugs to be made available - either to buy, or to be given away free.
'As for performers, we'd say their ears are their livelihoods and for a DJ or a drummer, to be able to hear what you're playing or mixing is the key to doing their job, so what we're saying is get a very good pair of earplugs: specifically, custom-moulded ones with filters that flatly attenuate, made specifically for your ears and which only cost about £150. We've got a number of celebrities involved who endorse the campaign: for example Sir Paul McCartney and Sir George Martin and also Moby, who has tinitus himself and takes it very seriously.'
Meanwhile, another manufacturer whose equipment you are likely to encounter when you turn up at a gig is the Dutch firm, Dateq, whose products are distributed in the UK by Sonic 8. Dateq's SPL limiters are now being introduced in the UK, says Sonic 8's MD, Stephen Helm, in response to increasingly tight enforcement of the legislation. 'Dateq has a whole range of sound protection limiters, and their latest, the SPL 5, has a lot of advantages - not least that it avoids the "pumping" effect you can get from some other systems. They also don't cut-out: when you abuse the system, all it does is turn it down. Who wants the whole system to suddenly switch off?'
Again, this is not expensive equipment - the most expensive Dateq box will set a venue back just under £800. 'The SPL 5 has an extra advantage,' says Stephen Helm. 'It wll give you a 60 day printout, showing peaks and averages and something like that can save somebody's licence. Imagine you've had complaints about noise on such and such a day and you are able to produce a printout showing exactly what you had done. It also lets a venue tell which DJs are abusing the system, because it shows the dates and times, which can be very useful if you are trying to protect your licence.'
One useful benefit to all of the noise-limiting systems on the market is that they can also offer valuable protection against freelance idiots who crank the system to speaker-destroying levels - no laughing matter given some of the ultra-expensive rigs being installed in clubs these days!
Very much at the sharp end of all these considerations is Dr. Douglas Doherty, whose Newcastle-based company DACS, acts as an acoustic consultant to a wide range of venues and studios, both in the North of England and the even more tightly-legislated, Scotland.
There have been rumours that one day legislation might be aimed not just at venue owners, but at performers, too (a chilling prospect for any band or DJ). Fortunately, Dr. Doherty feels it would be very difficult to implement, were the idea ever to be seriously proposed. 'I can't see how it would work. Take a performer like Michael Jackson. He is probably five levels removed from any control of the out-front sound pressure levels and to some extent you would have a similar problem with a DJ in a club. He's using a system which he doesn't know and has no control over and though he's probably more connected, he would have to be able to measure and adjust the system to comply so, no, I can't see that working. It would be immensely difficult to hit the performers, because they can't actually control the problem.'
However, the enforcement of existing legislation is undoubtedly tightening, he has found. 'There is a problem here,' he says. 'The way exposure is calculated means that if someone working in a club is exposed to eight hours at 85dB(A), he can work four hours at 88, two hours at 91, one hour at 94 and half an hour at 97. For some people working in nightclubs, then, they must be well in excess of those limits, but it is still a very grey area and you have to assume that before long there is going to be a whole army of solicitors out there getting ready to tout for business.
'Either way, this generation of club-goers is going to be the next deaf generation. There was the shipbuilding and industrial deafness generation who are now in their sixties, there was my generation and now there is one coming up, the club generation, which is going to suffer serious deafness.'
There are several issues here for performers to think about. On the one hand there is the responsibility we owe ourselves to keep our hearing sharp - and to take the precautions necessary. Beyond that, there is the need to keep on the right side of the law which, even if it doesn't directly affect performers, certainly does affect the venues in which we play - which means, increasingly, we are going to find ourselves being monitored and controlled. There may be, also, as the RNID suggests, a moral responsibility not to inflict hearing damage on our audiences. In the end, in an increasingly regulated world, this is no longer an issue we are going to be able to shrug our shoulders and ignore. Or, you might say, to turn a deaf ear to.
Formula Sound: 0161 494 5650 Web: www.formula-sound.com
Sonic 8: 08701 657456 Web: www.sonic8.com
DACS Ltd: 0191 438 2500 Web: www.dacs-audio.com
RNID: 0808 808 6666 Web: www.dontlosethemusic.com