“db” in physical Noise Levels, Analog Audio Equipment, Digital Sound Software. What are these and how they relate? Why are conversations at “60dB” and why is a Digital Software scaling it from negative to zero?

Question

If in Digital Sound Software there’s a meter from -60 to 0, what’s the best “range” (for the lack of knowledge) of sound someone can record at? Considering that people who will listen to that recording can adjust their speaker volumes up and down.

In: Engineering

Answer 1

dB are a way of listing relative values that cover huge ranges

A sound at 60 dB_spl is 1000 times louder than the quietest sound you can detect. A jet engine at 140 dB_spl is 10,000,000 louder than the quietest sound you can hear. Negative dB levels are smaller than their reference level.

The trick is figuring out what the reference level is. For sound it’s the smallest pressure change you can hear so sounds you can hear are positive dB values while ultra quiet rooms have negative values. Amplifiers show their output relative to their maximum output so their numbers are usually negative

So why are dBs helpful? Because many of our senses also work on a logarithmic scale like dB. You perceive a sound to be twice as loud when it has increased by 10 dB. It’s easier to work with a calm room being 30 dB and a conversation being 60 dB than 632 uPa and 20 mPa