A Phonetic and Phonological Approach to Stress in Sinhala Verbs

research on stress and stress perception has primarily focused on the acoustic characteristics of stressed versus unstressed syllables, and how listeners make use of acoustic cues to make judgements as regards the occurrence of stress. Most phoneticians agree that the three acoustic dimensions involved in the realisation of stress are duration, fundamental frequency, and intensity. These acoustic properties correspond to the perceptual phenomena of length, pitch, and loudness, respectively. Some phoneticians also include vowel quality as an additional dimension (Laver 1994, Hayward 2000). In general, stress is described as the display of prominence by the exaggeration of one or more of the phonetic parameters on certain syllables when contrasted with others (Laver 1994). Hence, a syllable displaying such prominence can be said to have possibly longer duration, higher pitch, greater acoustic intensity, and more carefully articulated phones when in contrast with unstressed syllables (Hayward 2000). However, some linguists make more specific claims as to which parameters play a larger role in the realisation of stress. Ladefoged (2003) states it is likely to be some combination of pitch, length, and loudness, with the first two playing the greatest role. To further complicate the phonetic description of stress, it appears that its phonetic manifestation varies from language to language (Laver 1994). Based on many studies conducted on English stress, Laver claims that English exploits all four parameters. However, studies conducted by Fry (1955) claim that English relies heavily on duration and intensity. In another study conducted by Mol and Uhlenbeck in 1965 in which the intensity relationship of stressed and unstressed syllable was reversed, it shows that intensity did not affect the perception of stress (Cutler 2005). On the other hand, Fujimura and Erickson (1997) state that stress is primarily manifested in the change of the fundamental frequency. In summary, Cutler asserts that the least controversial findings as of today are (1) syllables are perceived to be stressed if they exhibit fundamental frequency excursion and (2) greater syllable duration is likewise associated with perceived stress. The more controversial finding is that intensity manipulations only weakly affect stress perception, such as the findings shown by Mol and Uhlenbeck. As for the muscular activities involved in the production of stress, Hayward (2000) says that stressed syllables display raised subglottal pressure when compared with unstressed syllables. This increase in pressure can be accomplished by respiratory activity, by laryngeal activity, or a combination of both. Another …