Re: [css3-speech] voice-pitch

On 14/07/2011 3:26 AM, Daniel Weck wrote:
> On 13 Jul 2011, at 17:56, Daniel Weck wrote:
>> Okay, let me publish an update to the pitch properties, where the
>> CSS notation is aligned with SSML's calculation method. I will then
>> ask the CSS syntax / parsing gurus to review the correctness of the
>> prose. :)
> Could you please review the updated prose:
> The pitch-range definition of percentages is identical:
> Thank you very much! Daniel

In regards to the semitone value.

   | <semitones>

   | Specifies a relative change (decrement or increment)
   | to the inherited value. The syntax of allowed values
   | is a <number> followed immediately by "st" (semitones).
   | A semitone is half of a tone (a half step) on the
   | standard diatonic scale. As such, a semitone doesn't
   | correspond to a fixed frequency: the ratio between
   | two consecutive frequencies separated by exactly one
   | semitone is the twelfth root of two
   | (approximately 1.05946).

The above does not quite sound correct. Part of what the WD says above 
concerning the 'twelfth root of two' [1] is actually the ratio scaling 
of the 'chromatic scale' [2] with has all steps a semitone apart and an 
even ratio increase/decrease in hertz. The 'diatonic scale' does not 
have this even scaling and it only has seven steps 'T-T-S-T-T-T-S'.

I also don't understand what the WD means by the part which says 'a 
semitone doesn't correspond to a fixed frequency'?


Alan Gresley

Received on Thursday, 14 July 2011 14:58:24 UTC