Help me understand the difference between 28dB, 38dB and 48dB.

November 21, 2013 5:12 PM

Help me understand the difference between 28dB, 38dB and 48dB. I'm thinking about buying a fridge, and the fridges I'm considering have noise levels ranging from 28dB to 47dB (according to the latest fridge assessment in Choice). Fridges with a 28dB noise level rating are too expensive for me, though, so I'm trying to find something I can afford but which won't annoy me too much (I'm sensitive to the noise of a buzzing fridge). What I can afford tends to be somewhere in the mid-30s dB range. But it's no use going into a noisy showroom and trying to properly gauge how a fridge will sound in my quiet home. So I'm wondering if there's a way I can test these different noise levels at home before I buy, to see what's the difference.
posted by paleyellowwithorange to Science & Nature (9 answers total)

Best answer: Look up the dB level for your current fridge (or washing machine/other appliance)?
posted by travelwithcats at 5:15 PM on November 21, 2013 [1 favorite]

Best answer: Comparative examples of noise levels chart.

Rough rule of thumb: an increase (or decrease) of 3dB is a barely noticeable increase (or decrease) in volume.
posted by Pinback at 5:20 PM on November 21, 2013

Best answer: I think this is one of those things that appliance manufacturers say to make you think there's a significant difference between the different products, when in fact the differences have no practical impact. But they do it so they can charge you more. (See also - the number of megapixels on a digital camera).

I did a quick Google search for "decibel levels of everyday sounds" and here's the first link that comes up: www.asha.org/public/hearing/noise/

So the 28dB fridge would be a little bit quieter than a whisper, and mid 30s dB would still be quieter than a quiet room. 48db would be a little quieter than moderate rainfall.

There were obviously lots of other links returned by Google so have a look through to get some more real-world examples.
posted by infinitejones at 5:21 PM on November 21, 2013

Best answer: A general rule of thumb is that perceived volume doubles every 10dB (source). So the 38dB fridge is going to sound twice as loud as the 28dB one, and the 48dB one twice again as loud.
posted by zsazsa at 5:25 PM on November 21, 2013 [1 favorite]

FWIW, as another rule of thumb, take the evaluations by Choice with a huge grain of salt. Whenever I read their articles on subjects I am extremely familiar with I have huge issues with their focus, their criteria, their methodology, and their general approach.

Yet somehow, despite their evaluations being totally wrong-headed, they usually still come to the same or similar recommendations that I would give. I'm not sure how they manage that…
posted by Pinback at 5:34 PM on November 21, 2013 [1 favorite]

Best answer: If you have a smart phone, you can download a decibel meter app, then use it around the appliances you have at home to get a sense of what each level sounds like.
posted by MelissaSimon at 6:22 PM on November 21, 2013

What the broadband dB rating doesn't tell you is if there's an annoying tone to the appliance's output. Your ears are great at picking up tones, so even quiet ones can be annoying.
posted by scruss at 6:24 PM on November 21, 2013

I have a very noisy fridge and believe me, "moderate rainfall" coming from the kitchen at 3am is a real pain. Go for the quiet one.
posted by johngumbo at 9:28 PM on November 21, 2013

From some stuff I do at work, 40 dB is what a carpeted 20' by 25' room with just a air handler and a regular dell desktop computer running in the corner sounds like.

This depends on the weighting though.

take the 38 dB one if you can.
posted by ArgentCorvid at 5:56 AM on November 22, 2013