Skip to main content

Decibel readers and iPhone apps

If you're having noise problems in your home or business, you can measure the decibel level with inexpensive apps on your iPhone or buy a decibel-reading device.

I downloaded a free app from the App Store called "Decibels" and purchased an inexpensive one - with more features -- called "SPL Meter," but there's many to choose from (just search for "spl meter"). Basically these apps help you measure the decibel volume in your home when it's quiet, and again in different noise situations -- your neighbor's TV or stereo, the sound of cars and trucks outside your windows, the sound of barking dogs, crying babies, etc.

[update, Dec 2013: see this review of 30 decibel-reader apps.]

All rooms have a decibel level, even when you think you're sitting in silence. So let's say the dB level in your home is 40 when it's quiet, but increases to 60 when your adjacent neighbors watch TV on their home theatre system. What does this mean when you look for soundproofing solutions? You need to research the STC (Sound Transmission Class) of the sound-control products -- the measurement at which they filter out noise in dB.

Let's say that a typical American home is built on a wood frame with 5/8-inch gypsum walls and ceiling (approximately STC 40). Assume that the walls and ceiling are nailed directly onto hollow studs. At best, your home can only filter out 40 dB of sound. When it's quiet, no problem. But if your neighbors' TV comes through your walls and increases the noise level to 60 dB, you need a solution that delivers a minimal STC of 60, and preferably more.

STC is not everything

Of course, STC ratings alone don't cover all the acoustical quirks in your situation -- you might have flanking noise, resonance from something you can't control in the building, and other types of noise and considerations. But if you can measure the dB level of noise in your home under optimum conditions and then measure again when you have a common noise intrusion, you have some hard data when you search for a solution.

Here's more information on dB and acoustical terminology and statistics.
This glossary of acoustical terms offers lots of definitions, but not in layperson's language.
This decibel chart lists the basic level of everyday noises, all the way up to noise that induces hearing loss.

You can learn how some of these meters work through watching YouTube videos. For example, this hand-held SPL meter can be adjusted for frequency range and response rate. And this YouTube video compares a multimeter to a decibel meter app on an Android. A professional noise analyzer offers weighted readings that are often more precise than some of the smartphone apps.

Update in 2023: I made this video of my favorite decibel meter app -- which is called "Decibel Meter." It's only available on iPhone. What's great about it is that it shows the decibel levels (in dBA or dBC), and it also shows you the frequency readings at the same time. This makes a difference when you compare a 65-decibel conversation to the sound of leaf blower down the street, which might also read as 65 decibels. One of those sounds will have a very low frequency, which is why it's so annoying!



Labels:

Comments

  1. AnonymousJune 24, 2012 at 10:52 AM

    Hi - just found your blog. Very interesting. I own sound level meter and use it periodically to check out the level of noise around me.

    Your information on soundproofing looks good.

    Craig

    ReplyDelete

Post a Comment

Popular posts from this blog

Combining QuietRock and Green Glue together

Two great products work great together. As I've mentioned before, I'm experimenting around with ways to reduce some of the noise problems in my apartment on a tight budget. I think I've found the best combination to date: adding a layer of QuietRock 510 over an existing layer of gypsum drywall with a layer of Green Glue inbetween. This was sort of the best of both worlds: taking a pre-made, sound-dampened drywall and then adding it over a powerful, viscous layer of glue....onto drywall that was already on the wall studs. No demo needed. In this project, I basically added two sound-dampening layers to the original 1950s drywall (one layer in the QuietRock and the other layer created by the Green Glue) to address " flanking noise ": feet, furniture, and shoes pounding on the bare floor of my downstairs neighbors' apartment. The amount of banging, bashing, and foot-stomping sounds coming from their very "wooden" apartment has been severe, and I...
10 comments
Read more

How to measure decibels and frequency with the Decibel Meter app

 Frequency matters When you're dealing with a noise issue, the frequency of that noise is just as important as the decibel level. A decibel is the loudness of the sound, and measuring decibels can alert you when a sound is more than just a nuisance, but dangerous to your health. However, decibel levels on their own don't tell the whole story. The frequency of the sound is also very important. The frequency is a measure of how many sound waves per second are produced by a sound, and determines its pitch. A low-frequency sound might be really annoying, but it might not be that loud. The lower frequencies are typically below 150 Hz, and often sound like a deep bass sound that's not necessarily loud, but the vibrations from that sound can travel through the entire frame of a building and disrupt sleep or cause stress. Knowing both the decibel level and the frequency of an unwanted sound can help you determine the right soundproofing solution. For example, a low-frequency nois...
Post a Comment
Read more

Why a decoupled ceiling might not eliminate all noise

A decoupled ceiling might eliminate most of the noise between floors, but not all of it.   If you're thinking of decoupling a ceiling in your home or apartment, you might not eliminate all the noise between two floors. This doesn't mean that it's not worth doing. It means that resolving noise issues in your home might be an iterative process. Because after you address one noise source, you might discover another one. Noise paths A noise path is how a noise enters another space. For example, this could be through the air or through a thin wall, through the joists and studs in a building frame, through a wall outlet, or through a vent. You might soundproof one noise source only to realize afterwards that there were other points of entry for that noise. So if you're thinking about removing your existing ceiling and decoupling it with soundproofing materials, keep in mind that some types of noise might be coming from different sources via different paths. You might reduce o...
Post a Comment
Read more