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A practical guide to measuring sound levels.
You'll Discover:
- How to measure outside noise to know your rights.
- Measure and set internal sound for patron safety.
- Why background noise is important.
- How to avoid being a residential sound scapegoat.
Many venues have told us that it's hard to find practical guides on how to measure sound levels, in relation to the noise limits applied to their venues. We suspect that practical guides are scarce because organisations don't want to be criticised on their advice.
But that leaves venues in the dark, and we think it's better to have a strategy than not! So in this guide we're taking a punt to translate the jargon and rules into something that we hope helps.
1.
Measure sound levels to know your rights!
Get a Sound Pressure Level (SPL) meter to measure loudness in decibels:
Google around if you're after a highly accurate SPL meter, but to get you started, download a phone app like DB Meter Pro (pictured below). Try the free version or pay $15 for full features.
Importantly, you want a DB meter that allows you to record to get an average decibel sound reading over a period of time. You'll see later why that's useful.
Once you have an SPL meter you can try different sound setups and volumes in your venue to identify what works. For context, a person talking normally 1 metre away from an SPL meter usually reads as 60 to 65 decibels.
2.
Check internal sound
A venue’s licence conditions usually outlines specific noise limits - or acceptable decibel levels. Please check those.
But as a rough guide, hold the SPL 3 metres away from the sound source to see if it’s within typical levels:
- Piped restaurant music — 65 to 75 decibels.
- Background music in other parts of venue — 80 to 95 decibels.
- Soloists/duos — 85 to 105 decibels.
- Other small bands — 95 to 110 decibels.
- Small rock band — 105 to 120 decibels.
As a rule of thumb for the safety of patrons and staff, it's best to avoid sound levels that average above 100 decibels in any given hour. Hearing damage can occur if exposed to sound averaging above 100 db per hour.
As a test, set your SPL meter to show the average, and record 1 hour of sound during a live performance. If the results average is over 100 db, it's best to lower the volume.
Get your staff/sound engineer to check SPL routinely throughout shows, and help performers to turn back down if they creep beyond acceptable levels on their amps, instruments or through the PA.
3.
Background noise and outside noise limits
Understandably, the biggest issue for venues is complaints - however unfounded - on outside noise from the venue.
This City of Sydney Guide states that:
- Between 7am and midnight, noise from a licensed venue as measured at the edge of a residential property should not exceed the background noise level by 5 decibels (dB).
- Between midnight and 7am, noise from a licensed venue as measured at the edge of a residential property should not exceed the background noise level. Additionally, noise should not be audible within any habitable room of the residential premises*.
The City of Sydney defines background noise level as “the environmental noise levels at the affected property in the absence of any licensed premises noise”.
Roughly put, the background noise level that matters to you is the decibel reading next to the nearest residential property to your venue, when your venue is making noise, versus when you're not making noise. When you're making noise, the SPL meter shouldn't measure more than 5 decibels above when you're not making noise.
4.
Measure your contribution to outside noise
Here's what most guides shy away from: suggesting how to measure noise to protect your rights! We've come up with a few strategies - that while a little fussy, and not airtight - at least put you in a more informed position to counter noise complaints that you don't think your venue is responsible for.
Step 1. Measure average background noise at a time of day when you plan to make sound, but before you do (eg just before a band starts):
- Take your SPL meter to the nearest residential property. Set it to show and record the average DB. Assuming any sound your venue is currently making is negligible, record a SPL reading of the background noise level for 5-10 minutes. That recording needs to show you the average decibels across that recording time.
- Save that recording, specifying the day and time - eg Recording 1: background noise Saturday 9pm.
Step 2. Measure your venue's contribution to background noise:
- Start up your usual sound - eg in house sound system or a performing act. To be really specific you could play the same song at the same volume during step 2 and step 3.
- Now go back to the nearest residential property and record for the same duration as you did for your first recording.
- Make sure there's no other loud sounds that have been added to the background noise since you took that 1st recording. Remember you're getting an average sound over time, so a loud crowd that wasn't there before or a cop car siren could push up the average sound decibel.
- Save as Recording 2: background noise with venue sound Saturday 9:15pm.
If recording 2's average is more than 5 decibels above recording 1, your venue might be exceeding acceptable noise limits. If it's over redo recording 1 and 2 a few times to ensure that something else hasn't pushed the average sound up.
Step 3. Measure your venue's internal sound at the time that you're compliant with outside noise limits established in recording 2:
- Once you've established that recording 2 isn't 5db over recording, make a 3rd recording in your venue. Record where you think your venue is most likely to spill sound outside towards residential properties eg near a door or windows. Record when you're making similar sound to recording 2 (eg when the band is playing, or a song at similar volume to step 2). Record for the same duration of recordings 1 and 2.
- Save as Recording 3: Venue sound when compliant with noise limits Saturday 9:30pm.
- Recording 3 means you don't have to go outside/ to residents to know if you're venue is within noise limits. Now if you're ever concerned you may be exceeding outside noise limits, make a fresh recording and see if it's average is equal or below recording 3. If so, you know you can counter any complaints you may receive for that time of day, by demonstrating that you know how to measure and monitor your sound compliance.
Step 4. Don't forget to measure at different trading times:
Street, pedestrians and other business noises make up the background noise, and that increases or decreases based on times of day. Eg Friday nights may be louder near your venue even if you weren't open. So repeat steps 1-3 for different times of day to get average readings that allow you to counter unfounded complaints that don't take into account times of day, and aren't as informed as you are!
5.
Don’t let residents make you a scapegoat
Watch out for residents that confuse your venue’s 5db contribution on top of background noise with the actual background noise of the street, pedestrians, other than your patrons, and other things out of your control.
Most venues program entertainment at times when background noise is higher than usual (ie busy weekends or evenings). If your venue was closed, that background noise would still be there.
If residents are claiming that you’re causing the noise, be sure to get a background reading at the time of day/night in question during and after your events to help rule out your venue’s contribution. Seek assistance from the City of Sydney to manage complaints.
6.
Resources
For more information on grounds for noise complaints and suggestions on how to deal with a complaint, check out these resources: