[DECtalk] Too high-pitched notes, and DecTalk sounds distorted

[Talksina]

yes OK, I understood, I know the DecTalk numbers are as the keyboard piano
13=c, 14=c#
15=d, 16=d#
17=e, 18=f, 19=f#, 20=g, 21=g#, 22=a, 23=a#, 24=b, 25=c one octave
higher, and so on.
The trick is always the herz frequency, but I suppose, as DT is
properly programmed to sing, unlike Loquendo that isn't, programmers
have just created this quite simple incrementing numbers scheme, to
make it easier for people to learn.
Maybe, assuming that most people who decide to make dt sing, are quite
familiar with music instruments and notes. I am a bit familiar with
piano keyboard, even if it's almost 17 years I do not play any longer!
PS I changed e-mail address, as that Libero was a crap