Click here to go to help on Stress and Syntactic Symbols for a complete list of symbols.The Hat rise (hr) option (nominal hat rises in Hz) and sr (nominal stress impulse rises in Hz) options determine aspects of the dynamic fundamental frequency contour for a sentence. To modify these values selectively, you should understand how the f0 contour is computed as a function of lexical stress pattern and syntactic structure of the sentence.
A sentence is first analyzed and broken into clauses with punctuation and clause-introducing words to determine the locations of clause boundaries. Within each clause, the f0 contour rises on the first stressed syllable, stays at a high level for the remainder of the clause up to the last stressed syllable, and falls dramatically on the last stressed syllable. This rise-at-the-beginning and fall-at-the-end pattern has been called the hat pattern by linguists, using the analogy of jumping from the brim of a hat to the top of the hat and back down again.
The hr option indicates the nominal height, in Hz of a pitch rise to a plateau on the first stress of a phrase. A corresponding pitch fall is placed by rule on the last stress of the phrase. Some speakers use relatively large hat rises and falls, while others use a local impulse-like rise and fall on each stressed syllable. The default hr option value for Paul is 18 Hz, indicating that the f0 contour rises a nominal 18 Hz when going from the brim to the top of the hat. To simulate a speaker who does not use hat rises and falls, use the command:
[:dv hr 0]
Other aspects of the hat pattern are important for natural intonation but are not accessible by speaker-definition commands. For example, the hat fall becomes a weaker fall followed by a slight continuation rise if the clause is to be succeeded by more clauses in the same sentence. Also, if unstressed syllables follow the last stressed syllable in a clause, part of the hat fall occurs on the very last (unstressed) syllable of the clause. If the clause is long, DECtalk Software may break it into two hat patterns by finding the boundary between the noun phrase and the verb phrase.
If DECtalk Software is in phoneme input mode and you use the pitch rise [ / ] and pitch fall [ \ ] symbols, the hr option determines the actual rise and fall in Hz.
Click here to go to help on Stress and Syntactic Symbols for a complete list of symbols.