Originally Posted by Bryanccfshr
Off topic, but not really. Decibel measurements are not linear. In fact the difference in intensity you described is significant.
However perceived noise is highly individual and is subject to the wavelength of the noise. Decibels measures sound pressure and the intensity based on a logarithm ." On the decibel scale, the smallest audible sound (near total silence) is 0 dB. A sound 10 times more powerful is 10 dB. A sound 100 times more powerful than near total silence is 20 dB. A sound 1,000 times more powerful than near total silence is 30 dB"
https://science.howstuffworks.com/question124.htm
I do noise surveys and personal dosimetry as part of my profession.
Noise is highly misunderstood.
Originally Posted by PimTac
Since this subject comes up pretty frequently here I thought I would provide some evidence. This is still not scientific but it's a step up from just "earsay".
I just changed my oil in the Mazda. The engine was warmed up. I used a decibel reading app in my iPhone to see what difference if any there was between old and new oil. I had the phone in the same spot for each reading.
With the old oil the average reading was 74.4 decibels. The new oil average reading was 73.8 decibels.
Now, did the engine sound quieter to me? I will say yes but the decibel readings are not significantly that far apart to make a difference. My guess is that it's a difference tone or frequency of noise.
So based on all this, there is no difference.
Interesting stuff. Thanks for linking that. It also doesn't help that I am deaf in one ear and probably not 100% in the other.