  This paper investigates the temporal excitation patterns of creaky voice.
Creaky voice is a voice quality frequently used as a phrase-boundary marker,
but also as a means of portraying attitude, affective states and even social
status. Consequently, the automatic detection and modelling of creaky voice may
have implications for speech technology applications. The acoustic
characteristics of creaky voice are, however, rather distinct from modal
phonation. Further, several acoustic patterns can bring about the perception of
creaky voice, thereby complicating the strategies used for its automatic
detection, analysis and modelling. The present study is carried out using a
variety of languages, speakers, and on both read and conversational data and
involves a mutual information-based assessment of the various acoustic features
proposed in the literature for detecting creaky voice. These features are then
exploited in classification experiments where we achieve an appreciable
improvement in detection accuracy compared to the state of the art. Both
experiments clearly highlight the presence of several creaky patterns. A
subsequent qualitative and quantitative analysis of the identified patterns is
provided, which reveals a considerable speaker-dependent variability in the
usage of these creaky patterns. We also investigate how creaky voice detection
systems perform across creaky patterns.
