This table represents the values to set in the tag of the table it’s used to set Pepper’s voice:
tag | value | |
Voice height | \ Vct = 135 \ | 50 to 200 |
Voice speed | \ Rspd = 110 \ | 50 to 400 |
Weight | \ Pau = 1000 \ | 1000/1 second |
Voice volume | \ Vol = 50 \ | 0 to 100 |
The default settings makes quite hard to to listen to long sentences and the voice height is a bit too low, so when speaking quite a bit, the speed is around 90 or 100 and the height of the voice depends on the words. Normally I am using about 170 lines when I am happy with about 145 or when my tension is rising.
You may try setting the intonation only by the height of the voice, but I think that it will not work as you are expecting because words will be chopped when you set the voice height setting to shred words.
Here at this link http://doc.aldebaran.com/2-5/naoqi/audio/altexttospeech-tuto.html you can find more detailed information that covers also other customisation capabilities of ALTextToSpeech module.