Yes, David is right. I agree that the editing procedure should be done
at a higher resolution than 16 bit. But that does not mean that you
need to initailly record in 24 bit! The format conversion can simply
be done before starting the editing procedure (most audio editing
applications do that automatically).
We naturerecordists usually deal with relatively low dynamic ranges
that can be easily covered by the 16 bit format. Even if you record a
loudly singing bird at a close distance, the sound level at the
microphone will usually never reach 80 dB. Then subtrcat the self
noise level of the microphone (e.g. 5 dBA if you have a good very good
one) and you will get a theoretic dynamic range of about 75dB only.
So, there is still enough head and foot room within the theoretic
dynamic range of the 16 bit format (96dB). Please note that I still
have not included the background noise (such as traffic noise, wind
noise and so on) into that calculation...
Raimund
David Ellsworth <> wrote:
>
> At 2007-05-13 08:24, Lou Judson wrote:
> >There is much to "lose" by not using 24 bit - it is not signal to
> >noise per se, but finer gradation of detail, and a wider range of
> >processing that can be done with 24 bit.
> >
> >The point of the articles you quote is that if the preamp noise is so
> >bad then 24 bit won't sound better, but that is wrong. 24 bit gives
> >far more definition, especially if any processing will be done to the
> >audio - even just a simple change in level or a fade out. And any
> >software attempt to remove noise will be more successful in 24 bit.
> >It is somewhat similar to the difference between cassette and reel
> >tape in my experience.
>
> But, the same depth of processing would be possible after a
> 16-to-24-bit conversion. As long as your noise floor is significantly
> louder than -90 dB (20*log(1/2^(16-1))), there will be no significant
> difference, except for the savings in storage space with 16 bit.
>
> The noise floor is only going to be on the order of -90 dB if you
> have the gain set low in order to get extreme dynamic range (catching
> the subtleties of a very quiet background ambience while also
> capturing very loud intermittant sounds) or to avoid ever needing to
> change your recording volume (which could be useful for science, i.e.
> measuring absolute loudness of sounds recorded).
>
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