Re: [linux-audio-user] Linux music editor, greater than 32-bit ?

From: Brad Fuller <brad@email-addr-hidden>
Date: Thu Mar 01 2007 - 00:07:22 EET

Arnold Krille wrote:
> Hi Paul and all (that rhymes :-),
>
> 2007/2/27, Paul Winkler <pw_lists@email-addr-hidden>:
>> On Tue, Feb 27, 2007 at 10:40:46PM +0100, Arnold Krille wrote:
>> > 120dB is the difference between just loud enough to be heard by your
>> > ear (1dB) and the loudness when the bones in your ear bow to protect
>> > it. At higher levels (>120dB) your ear aches but it will recover if
>> > the noise isn't permanent. At least thats the definition I learned...
>> I got my numbers from http://en.wikipedia.org/wiki/Decibel#Safety but
>> obviously their numbers represent some sort of typical examples; I
>> been in a number of discotheques (here in the US we can't pronounce
>> that so we just say "clubs") that had sound levels far above 100 dB.
>> The amount of time the ear can be exposed to a given sound pressure
>> level before sustaining permanent damange clearly varies a lot from
>> person to person. But government standards are probably a good
>> guideline to start with, eg. OSHA table G-16:
>> http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9735
>>
>
> I stand corrected, my numbers where from my physics-book which states
> that 120dB is the "Schmerzgrenze" and 0dB is the slightest whisper
> human ear can hear. Problem is that these values vary on the frequency
> so there is a correction curve standardised(?)

  Fletcher-Munson did the first (I believe) curves:
(http://en.wikipedia.org/wiki/Fletcher-Munson_curve

Others have refined.

see more: http://en.wikipedia.org/wiki/Equal-loudness_contours

> in some A-something
> paper so these corrected values for the human ear are called db(A)...

Yeah... dB doesn't mean a whole lot unless there is a reference.
see also: http://en.wikipedia.org/wiki/A-weighting

The OSHA standards _are_ important, so it's good that you listed them.

-- 
brad fuller
  http://www.Sonaural.com/
  +1 (408) 799-6124
Received on Thu Mar 1 04:15:02 2007

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