Register and speech variation.

There are several speech parameters that are known to vary radically with different speech registers. One of the primary concerns of sociolinguists has always been the degree to which speech ‘‘style’’ and ‘‘register’’ influence speech production; this variability is now of greater concern to members of Acoustical Society because the variation influences intelligibility of speech for machines, and of synthesized speech. This paper will discuss evidence that pitch contours, vowel reduction, and vocabulary choice are all influenced by register. This paper will focus on the use of the work ‘‘not,’’ analyzing the relative likelihood of pitch prominence, neutral presentation, or reduction (n’t) in three different registers. Data from political debates will be compared with data from small group ‘‘brainstorming’’ sessions and with data from a DARPA workshop. There will be a discussion of the importance of this variation to both automatic speech recognition and speech synthesis. [Work partially supported by NSF.]