Mehdi Bakhtiar

Objective Voice Analysis of Iranian Speakers with Normal Voices

OBJECTIVES Objective measurements in general and acoustic measurements in particular have become a substantial aspect of voice assessment during the last few decades and studies have established that normative data is necessary for acoustic analysis. Voice acoustic analysis including fundamental frequency (F(0)), jitter, shimmer, harmonics-to-noise ratio (HNR), and maximum phonation time (MPT) can now be easily recorded and analyzed using a computer. Because these systems are widely used in clinical practice, this study was designed to establish the normal acoustic analysis parameters in normal Iranian adults. METHODS A group of 90 unpaid, healthy, randomly selected subjects with normal voices (45 Iranian men and 45 Iranian women), was selected for this study. Data collection was carried out, using the Dr. Speech Software (subprogram: vocal assessment version 4.0 from Tiger Electronics) at the speech therapy clinic under comfortable phonation. Each gender was separated equally into three age subgroups. Then differences between gender and age subgroups were investigated by statistics software SPSS 13.0. RESULTS The value of (vowels /â/ and /i/) was greater for females (214.64+/-1.16; 228.06+/-1.5 Hz) than for males (112.82+/-0.94; 126.13+/-1.49 Hz). Conversely, the value of MPT was greater for males (26.30+/-1.29 s) than for females (18.56+/-0.88 s). There were no significant differences in average shimmer and jitter between females (1.21+/-0.03%; 0.22+/-0.01%) and males (1.22+/-0.02%; 0.23+/-0.02%). However, the value of HNR was greater for females (18.81+/-0.96 dB) than for males (18.42+/-0.57 dB). CONCLUSIONS The present study developed a body of normal data for various parameters of acoustic analysis in different age groups and genders of normal Iranian adults. It seems that the majority of voice characteristics of adults was relatively stable and did not change with aging between 20 and 50 years. However, the voice characteristics of adults older than 50 years were not recorded in this study and therefore require further investigation.

Intervention with the Lidcombe Program for a bilingual school-age child who stutters in Iran.

Objective: In this study, the immediate and extended effects of the Lidcombe Program were investigated for the first time in Iran. Treatment in the Lidcombe Program is carried out by the child’s parent (or carer) in the child’s everyday environment. The program has been shown to be effective with preschool children who stutter (i.e. younger than 6 years) and to a lesser extent with older children. Participant and Method: The participant was a bilingual (Baluchi-Persian) boy aged 8 years 11 months. Treatment was conducted in both languages. Stuttering severity was measured in Baluchi with the parental rating scale, and in Persian with percentage of syllables stuttered (%SS). Results: The child completed stage 1 of the program in 13 weeks. %SS was less than 1 during the last 3 clinic visits and severity ratings made by the parent indicated no stuttering (severity rating = 1) for all days of the final week. Speech recordings made beyond the clinic in both languages also indicated stuttering at below 1%SS. The child met all criteria for stage 2 in both languages, over 10 months. Conclusion: This case report suggests that the Lidcombe Program could be suitable for bilingual Iranian children who stutter.

Predictors of timed picture naming in Persian.

In this study, we report normative data by native Persian speakers for concept familiarity, age of acquisition (AoA), imageability, image agreement, name agreement, and visual complexity, as well as values for word frequency, word length, and naming latency for 200 of the colored Snodgrass and Vanderwart (Journal of Experimental Psychology: Human Learning and Memory 6:174-215, 1980) pictures created by Rossion and Pourtois (Perception 33:217-236, 2004). Using multiple regression analysis, we found independent effects of name agreement, image agreement, word frequency, and AoA on picture naming by native Persian speakers from Iran. We concluded that the psycholinguistic properties identified in studies of picture naming in many other languages also predict timed picture naming in Persian. Normative data for the ratings and picture-naming latencies for the 200 Persian object nouns are provided as an Excel file in the Supplemental materials.

Relationship between stuttering severity in children and their mothers speaking rate

CONTEXT AND OBJECTIVE Stuttering is a complex disease that influences occupational, social, academic and emotional achievements. The aim of this study was to correlate the stuttering severity index with speaking rates of mothers and children. DESIGN AND SETTING Cross-sectional study, at the child rehabilitation clinics of Tehran city. METHODS 35 pairs of mothers and their children who stuttered were studied. There were 29 boys and six girls, of mean age 8.5 years (range: 5.1-12.0). Speech samples from the mother-child pairs were audiotaped for approximately 15 minutes, until a reciprocal verbal interaction had been obtained. This sample was then analyzed in accordance with a stuttering severity index test and speaking rate parameters. RESULTS The research results outlined a significant relationship between the mothers speaking rate and their childrens stuttering severity. CONCLUSION The results suggest that the mothers speaking rate should be incorporated in the assessment and treatment of stuttering.

Motor control of speaking rate and oral diadochokinesis in hearing-impaired Farsi speakers

Although speech motor control has been studied intensively in normal-hearing and hearing-impaired (HI) speakers in America and Europe, essentially no research has been performed using Persian-speaking participants. A total of 46 prelingual hearing-impaired 15–18-year-old males and 15 normally hearing control participants from Iran participated in the study. Three speaking performance measures, oral diadochokinesis (DDK), speaking rate (words per minute), and intelligibility ratings, were obtained for the two groups and compared to previously published research for English-speaking participants. The DDK results in general showed that the normal-hearing group produced the fastest syllable rates, and the profoundly HI group produced the slowest. Similar results were obtained for speaking rates. Speech intelligibility was highest in the normal-hearing group and lowest in the profoundly HI group. Correlation analysis between DDK and speaking rates showed that for HI group only, a slow speaking rate corresponded to slow DDK rates. It is shown that generally there are significant differences in measures of speech motor control in normal-hearing and hearing-impaired participants. These results concord with those from other language groups.

Objective Vocal Parameters in Farsi-Speaking Adults with Down Syndrome

Previous studies have indicated significant differences in vocal parameters between children with Down syndrome and normal children. This study was performed to see whether there is a significant dissociation between normal adults and adults with Down syndrome in terms of some vocal parameters. The participants were 22 adults with Down syndrome and 22 normal adults matched for age and gender. We measured jitter, shimmer, fundamental frequency (F0), and maximum phonation time (MPT). The results showed a significantly higher F0 and a significantly lower jitter in the Down syndrome group compared to the control group, while the average amounts of MPT and shimmer were not different. Moreover, the shimmer and jitter of females in both groups were lower than those of males. These findings might be the result of a physiological retardation of the larynx rather than mental retardation in the Down syndrome population.

Lexico-Semantic Effects on Word Naming in Persian: Does Age of Acquisition Have an Effect?

The age of acquisition (AoA) of a word has an effect on skilled reading performance. According to the arbitrary-mapping (AM) hypothesis, AoA effects on word naming are a consequence of arbitrary mappings between input and output in the lexical network. The AM hypothesis predicts that effects of AoA will be observed when words have unpredictable orthography-to-phonology (OP) mappings. The Persian writing system is characterized by a degree of consistency between OP mappings, making words transparent. However, the omission of vowels in the script used by skilled readers makes the OP mappings of many words unpredictable or opaque. In this study, we used factor analysis to test which lexico-semantic variables, including AoA, predict the reading aloud of monosyllabic Persian words with different spelling transparencies (transparent or opaque). Linear mixed-effect regression analysis revealed that a Lexical factor (loading on word familiarity, spoken frequency, and written frequency) and a Semantic factor (loading on AoA, imageability, and familiarity) significantly predict word-naming latencies in Persian. Further analysis revealed a significant interaction between AoA and transparency, with larger effects of AoA for opaque than for transparent words and a significant interaction between imageability and AoA on reading opaque words; that is, AoA effects are more pronounced for low-imageability opaque words than for high-imageability opaque words. Interactions between these factors and spelling transparency suggest that late-acquired opaque words receive greater input from the semantic reading route. Implications for understanding the AoA effects on word naming in Persian are discussed.

Object and action picture naming in brain-damaged Persian speakers with aphasia

ABSTRACT Background: Individuals with aphasia can be impaired in action and object naming and most typically are more impaired when naming actions than objects. However, it is not clear if effects of grammatical class are language-general as assumed by some theories of speech production. Aims: We predicted greater impairments to action than object naming in persons with aphasia (PWA) in Persian. However, we expected any effect of grammatical class to be reduced when highly correlated variables are accounted for using generalised linear mixed-effects analysis. Methods & Procedures: PWA (n = 57) were presented with pictured actions (n = 80) and objects (n = 100) rated by 100 Persian speakers in a preparatory study for psycholinguistic variables such as familiarity, age of acquisition (AoA), imageability, name agreement and visual complexity. Outcomes & Results: 95% of PWA were more impaired on action naming than object naming. Rated AoA, name agreement, visual complexity and word length also significantly predicted naming accuracy for PWA and, there was an interaction between imageability and grammatical class such that imageability predicted object naming but not action naming. Conclusions: The effect of grammatical class on picture naming for PWA in Persian might be accounted for by differences in psycholinguistic characteristics of actions and objects. Although we doubt an independent effect of grammatical class on naming in Persian, we acknowledge that psycholinguistic variables can have differential effects on action and object naming in aphasia. We offer an account of spoken word production in Persian that assumes a functionally common pathway for naming actions and objects with no obvious constraint given by grammatical class.