Vowel variability and contrast in Childhood Apraxia of Speech: acoustics and articulation

none5noPhoneme production may be affected by limited speech motor control in Childhood Apraxia of Speech (CAS), with a general instability of acoustic targets across multiple repetitions of speech stimuli. This acoustic and Ultrasound Tongue Imaging (UTI) study shows that increased variability and reduction of contrast in vowel production is found in native Italian speakers with CAS, particularly as far as the height dimension is concerned. The data suggest that vowel production should play a major role in CAS diagnosis and treatment. Moreover, this study shows that a combined acoustic and articulatory approach allows direct observation of lingual dynamics together with an estimation of changes in the acoustic dimension. The two dimensions are shown not to correspond in a straightforward way in the speech of children with CAS, and encourage consideration of articulatory compensation strategies aimed at saving the acoustic identity of vowels.openLenoci, Giovanna; Celata, Chiara; Ricci, Irene; Chilosi, Anna; Barone, VincenzoLenoci, Giovanna; Celata, Chiara; Ricci, Irene; Chilosi, Anna; Barone, Vincenz

The Acoustics of Lexical Stress in Italian as a Function of Stress Level and Speaking Style

The study is part of a series of studies, describing the acoustics of lexical stress in a way that should be applicable to any language. The present database of recordings includes Brazilian Portuguese, English, Estonian, German, French, Italian and Swedish. The acoustic parameters examined are F0-level, F0- variation, Duration, and Spectral Emphasis. Values for these parameters, computed for all vowels (a little over 24000 vowels for Italian), are the data upon which the analyses are based. All parameters are examined with respect to their correlation with Stress (primary, secondary, unstressed) and speaking Style (wordlist reading, phrase reading, spontaneous speech) and Sex of the speaker (female, male). For Italian Duration was found to be the dominant factor by a wide margin, in agreement with previous studies. Spectral Emphasis was the second most important factor. Spectral Emphasis has not been studied previously for Italian but intensity, a related parameter, has been shown to correlate with stress. F0-level was also significantly correlated but not to the same degree. Speaker Sex turned out as significant in many comparisons. The differences were, however, mainly a function of the degree to which a given parameter was used, not how it was used to signal lexical stress contrasts.