Noise meets ear

+ The best way to consult communities on a project’s expected noise is to enable them to actually listen to, and experience, the sound from the proposed new trains, roads or airports.

Projects are normally required to do an environmental impact assessment (EIA) at an early stage. Noise will often form part of that EIA and is usually described in technical language that only a handful of specialists can easily understand. Just ask Joanne Public whether she thinks 50dBLAeq,18h outside her bedroom window is reasonable.

This techno-speak excludes non-specialists from the discussion, which seems at odds with a process that otherwise tries to be transparent. How am I, as a member of the community affected, going to judge what is reasonable if I don’t even know what it is I am being asked to accept? 

I think the best way to consult communities would be to enable them to actually listen to, and experience, the noise from the proposed new trains, roads or airports. That isn’t quite as easy as you might imagine, because the subjective impression we form of noise is mostly a function of difference – how much noise is there relative to what was already there? 

So to demonstrate noise, you have to show the whole picture, incorporating all the different noises surrounding you. It’s difficult, but it can be done. And it needs to be done.  

Finding ways for people to experience and understand sound is something of a passion at Arup. We started looking at this many years ago when we were trying to engage some of the artistic shareholders in decisions about the design of a concert hall. Having built our SoundLab, which can accurately create a fully 3-dimensional sound field, we found we could use it for other things too.  

By capturing the existing environmental sound with 3-D recording equipment we can overlay pretty much anything on to it. This means that noise can be demonstrated very effectively to people, and they can then form their own judgements. 

We’re starting to try this technique in community consultations on different projects to great effect.  This has included a large wind farm in Tasmania, the HS2 railway project in the UK and, more recently, demonstrations of aircraft noise. In many instances, people find that the noise they were worried about is not nearly as bad as they had been expecting. 

That shouldn’t detract from the need to control noise and vibration, which is still a major engineering challenge. But letting people experience noise for themselves means everyone can make a reasonable assessment of what is acceptable and what needs to be addressed.