decibel
Posted: Mon Mar 13, 2006 7:21 am
My first reaction was "Wow, looks like a college textbook!" Not to friendly to the layman, in that "definition" section.
Then down in the "Acoustics" section, I see a bunch of issues:
Hmm... see any mention of frequency in there? No, I don't either.Sound levels above 85 dB are considered harmful, while 120 dB is unsafe and 150 dB causes physical damage to the human body. Windows break at about 163 dB.
And I've sat in cars well in excess of 150dB without any physical damage to report.
And even MY sound quality cars all exceed 120dB easily, at least in the bass region.
They go on and on for so long, talking about these dB levels and "what effects they can have" - without one mention of frequency, and how it's a critical player - you can't publish a number like that without discussing what frequency would cause that effect, because "that effect" will happen at a different dB level, for any given different frequency.
And they mention at the top that dB chart that dB is a relative number... but don't discuss specifically how many dB reference "an audible change", vs "doubling of output", etc.
It's good, but I don't think great for the layman unfortunately.