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Re: information theory?
Posted:
Nov 4, 2011 7:14 AM
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<kym@kymhorsell.com> wrote in message
news:4eb3c38a$0$22471$afc38c87@news.optusnet.com.au...
> In sci.math Robert Wessel <robertwessel2@yahoo.com> wrote:
> ...
>> Consider that high keystroke rates pretty much require chords, and a
>> chord is most certainly not three or four random keys, pressed at
>> different times and forces - rather they're a small subset of the
>> possible combinations of keys within a hand-span (or two hand-spans in
>> some cases), hit at the same time, and with the same force (in fact
>> there are less than about 10,000 chords). And just like English, you
>> can't really have random sequences, or you'd just have noise.
>>
>> Still, 40bps intuitively feels a bit light, but not by that much. I
>> expect that if Shannon said something like that, he was considering
>> music to be more along the lines of a MIDI stream than a digitized
>> sound file.
> ...
>
> Perhaps we could use spoken language as a guide to the auditory bidrate
> we've evolved to process. As Shannon estimated, each letter in English
> has only a couple bits of entropy, with normal reading speed (that
> uses the auditory processing -- the reason you can't count the number
> of words in a limerick without using your fingers) around 150 wpm.
> Let's call that 25 bps.
>
> 40 bps is then about the "square" (in log terms :) of our evolved language
> processing speeds.
>
> Maybe not such a bad estimate.
>
> The same disparity is then seen between normal good voice compression
> and the actually bitrate we operate on. I.e. 25 bps "back-end" processing
> speed, yet voice compression being still 1000s of bps.
>
> In some applications over the years I've used speach-to-text and
> text-to-speach
> over very low speed lines as a slap-dash compression method. With a bit
> of a phoneme "nomenclator" it wasn't too bad. No doubt the idea is still
> in
> use, but I don't think I've heard of it in preference to straight dsp
> methods.
>
I had a play with a TI phoneme generator chip hooked up to a 6502
microproceesor in 1979 or 80. Couldn't get a decent "fuck" out of it - came
out as a flat "fut". Times have changed.
> --
> co2 has no climate forcing effect and is not a greenhouse gas and, for
> that
> matter, neither is water vapour.
> -- BONZO@27-32-240-172 [100s of nyms], 5 Sep 2009
>
> Earth's atmosphere contains natural greenhouse gases (mostly water
> vapor, carbon dioxide, and methane) which act to keep the lower layers
> of the atmosphere warmer than they otherwise would be without those gases.
> -- Dr Roy W. Spencer, "Global Warming", 2008
>
> This is what the real climate scientist Dr Roy Spencer said.
> -- BONZO@27-32-240-172 [daily nymshifter], 3 Mar 2011 16:29 +1100
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