Hi,
In message , Stewart Pinkerton
writes
On 17 Jan 2004 02:02:57 -0800, (Svante)
wrote:
However, this would actually speak against
using dB as a measure of distorsion, since dB is fundamentally
intended to measure a POWER ratio.
The dB was originally a measure of sound pressure level, and the
logarithmic scale is used simply becuause our ears respond to sound in
a logarithmic fashion.
I won't attempt to refute this statement, but I was under the impression
that the decibel (or rather, the Bel) was originally created in order to
simplify the calculation of relative electrical power levels in
telecommunication circuits. I think I read such in the Yamaha Sound
Reinforcement Handbook. Since I have no idea how accurate that source
is, I would be interested in finding out the real history.
I mean, the fundaments of dB
assumes that we measure a power ratio.
No, it doesn't. It is simply a useful logarithmic ratio.
I can't bring to mind any meaningful use of the decibel that is not
derived from power measurements, including dBSPL.
--
Regards,
Glenn Booth