American Journal of Psychiatry and Neuroscience 2014; 2(1): 13-17 Published online February 28, 2014 (http://www.sciencepublishinggroup.com/j/ajpn) doi: 10.11648/j.ajpn.20140201.13 Acoustical analysis of vowel duration in Palestinian Arabic speaking aphasics Hisham Adam Liberal Arts Department, American University of the Middle East, Kuwait City, Kuwait Email address: Hisham.al-adam@aum.edu.kw To site this article: Hisham Adam. Acoustical Analysis of Vowel Duration in Palestinian Arabic Speaking Aphasics. American Journal of Psychiatry and Neuroscience. Vol. 2, No. 1, 2014, pp. 13-17. doi: 10.11648/j.ajpn.20140201.13 Abstract: The current study investigates vowel durations of Arabic- speaking Broca’s aphasics. Three subjects diagnosed with Broca’s aphasia and three normal speakers participated in this study. Vowel durations of the short Arabic vowels (/i/, /a/, /u/) preceding voiced and voiceless fricatives were measured and analyzed. The effects of voicing on vowel duration are also investigated. The results show that the normal speakers as well as Broca’s aphasics complied with the phonological rule, vowels being longer preceding voiced fricatives. It is also demonstrated that vowel durations were significantly greater for Broca’s aphasics compared to normal speakers. Finally, this study is brought to bear on several aspects concerning timing and prosodic impairments of Broca’s aphasic speech. The finding may also have clinical applications concerning speech and language therapy in Palestine. Keyword: Vowel Production, Aphasia, Vowel duration, Neuroscience, Cognition 1. Introduction Much research has been devoted to investigate the durational and articulatory parameters of speech segments. It has been found that several aspects of vowel temporal parameters, including vowel duration, fundamental frequency, and formant frequency, are highly affected by speech intelligibility in both normal and disordered speech [12, 36, 24]. Vowel duration contributes to the listener’s ability to perceive vowels, in addition to providing information about vowel production mechanisms [15]. For example, it has been found that reduction of vowel duration accompanied by lax vowels compared to tense vowels is a result of decreased articulatory configurations required for the producing lax vowels [15].Accordingly, the measurements of vowel duration may demonstrate the degree of articulatory movements required to produce a particular vowel. Acoustic investigations also indicate that vowel duration is a perceptual cue for vowel identification and speech intelligibility [8,27]. Ferguson and Kewley-Port [8]reported from a significant impact of speech intelligibility on vowel duration, where vowels were perceived to be longer in sentences and phrases produced in a conversational style compared to those were addressed to individuals with hearing loss [9]. The acoustic literature reported from various temporal patterns concerning vowel duration. For example, it has been found that high vowels are shorter than low vowels, while vowels occur in open syllables are longer than vowels accruing in closed syllables [19]. Furthermore, vowels preceding voiced consonants were found to be longer compared to those preceding voiceless sounds, while vowels before fricatives are longer than vowels preceding stop consonants [19]. Vowel duration also was found to be affected by pitch and rate of speech. It has also been found that vowels spoken at slower rate were significantly longer compared to those spoken at faster rate[23]. Several studies have been carried out on the temporal and articulatory disturbances characterizing speakers with Broca’s aphasia and apraxia of speech [17, 5, 3]. In general, these investigations have raveled that Broca’s aphasic speech is agrammatic, nonfluent and dysprosodic. Broca’s aphasic speech is also characterized by a slow speaking rate with segment and syllable durations all being longer than those for healthy speakers [6, 3]. Vowel durations were found to be significantly longer among Broca’s aphasics compared to normal speakers. It has been proposed that Broca’s aphasics revealed temporal impairments, particularly abnormal lengthening of all speech segments [33]. In contrast, other studies found that Broca’s aphasics and speakers with apraxia of speech were able to maintain the intrinsic duration differences between tense and lax vowels and the durational patterns are