How to measure the noise from your simulator

You can check your hits with a phone, but treat the number as a rough guide. What matters most is taking every reading the same way, so you can see whether a change helped.

What the numbers are

Sound level is given in decibels, written dB. The scale is not a ruler. One source says a power change by a factor of 10 corresponds to a level change of 10 dB¹. So a few extra dB can mean a large change in sound energy.

You'll also see dB(A), or dBA. A-weighting is applied "to account for the relative loudness perceived by the human ear, as the ear is less sensitive to low audio frequencies"². The source gives the shorthand: "A-weighted decibels are abbreviated dB(A) or dBA"². Many meters offer an A-weighting setting, so check the manual for what yours displays. Since a low thump counts for less in dBA, a reading can look mild while a neighbour still feels the thud. Floor thud is better judged by listening in the other room.

Phone or meter?

A phone is easy. How accurate it is depends on the app. A study of iPhone apps found "significant variation in the ability of iPhone apps (Apple) to accurately predict environmental dB levels"³. Its conclusion was that with the right app, an iPhone is "a relatively reliable means" of measuring noise when a calibrated meter isn't handy³. That study tested iPhones only. It says nothing about Android phones.

Another source says most smartphone sound apps "are not accurate enough to be used for legally required measurements"⁴. It adds that calibrated microphones greatly improve accuracy⁴. So a phone is fine for before-and-after checks in your own room. It's a poor choice for settling an argument with a neighbour or an official complaint.

A basic handheld meter has its own limits, so look at what it claims. Does the maker say which standard it meets? Does it offer A-weighting? Read the manual for what it displays and how it responds.

How to take a reading

1. Choose one spot and keep to it. Mark it. Keep the phone or meter out of the hitting area and the ball's path. A phone on a tripod behind or to the side is better than one near the screen. Never hold it where a ball or club could reach it.
2. Take a reading with the room quiet first. That's your background level.
3. Hit several shots with the same club and note the number each time.
4. Do the same in the next room, or outside the wall you're worried about.
5. Change one thing, then repeat the quiet-room and shot readings.

Write the numbers down. Note the app or meter name, the phone, the distance and the club. If you swap the app, start over, because different apps can disagree³.

Reading your results

Compare your own numbers, not someone else's. Different rooms, phones and apps make outside figures hard to match to yours. A drop between your before and after readings means the change did something at your spot. A drop of nothing may mean the problem is a thud that dBA hides.

Listen as well. Ask someone to stand in the next room and say when they can hear or feel a shot. A person on the other side of the wall is a better judge than any app for a question like that.

Whoever holds the meter should stand outside the hitting area. Take a practice swing first to see where the club reaches, and keep any stand well clear of the screen.

For what to do with the results, see noise and the neighbours. To find the source of a loud reading, start with where the noise comes from.