جستجوی مقالات مرتبط با کلیدواژه « دامنه تغییرات بسامد پایه » در نشریات گروه « پزشکی »

Considered as an important factor in communication, prosody is composed of a number of features including intonation, pitch, stress, rhythm and duration, among others. Intonation is the variation of pitch in the course of producing a sentence. In this study, fundamental frequency range was defined as the minimum and maximum amounts of fundamental frequency one can produce when speaking a sentence. The aim of the present study was to evaluate two aspects of prosody, namely, fundamental frequency range and intonation contour in declarative sentences expressed by normal Farsi-speaking adults through laboratory procedures. Participants of this cross-sectional descriptive-analytic study were 134 males and females, aging between 18 to 30 years, who natively spoke Farsi. Voice samples obtained by having each subject produce 2 declarative sentences were analyzed by Dr. Speech program (real analysis software). Data were statistically analyzed via unilateral analysis variance and intonation contour was drawn for each of these sentences. The intonation contour was similar among two sex groups. However, fundamental frequency range of males during speaking the sentences significantly differed from that produced by female subjects (P ≤ 0.001). The intonation contour of declarative sentences was characterized by a falling status at the end of the sentence. Females showed much more changes in fundamental frequency in order to transfer declarative state in their expressions than males did.

Vocal nodules are non-malignant lesions of vocal cords caused by vocal misuse and abuse. Nodules can be viewed as the reaction of vocal tissue to a constant stress induced by frequent and severe movements. Acoustic signs of people with vocal fold nodules somehow differ from those with normal voice. However, there is no universal agreement on the exact amount difference between acoustics of normal voice and pathologic voice heard at the presence of vocal nodule and this, in turn, has resulted in different reported acoustic measurements. In this study, we used the standardized Rangin Kaman passage for vocal assessment of normal people and patients with voice nodule. In a cross-sectional descriptive– analytical study, 20 people with normal voice (10 males and 10 females) and 20 patients with vocal nodules (10 males and 10 females) with an age range of 40 to 59 years were randomly assigned into two age groups of 40 to 59 and 50 to 59 years. Each of these age groups included 10 subjects with normal voice (5 males and 5 females) and 10 ones with bilateral vocal nodules (5 males and 5 females). Thus, 20 voice samples were obtained from each age group. These voice samples were acoustically compared to each other on the basis of fundamental frequency and fundamental frequency variation range. Results showed that the differences in fundamental frequencies was significant when all samples were considered (P = 0.043). For detecting local differences, repeated analysis of variance was performed for men and women separately. In men, significant differences of fundamental frequency were neither observed between normal and pathological samples nor between two age groups as a whole (P = 0.59). In women, differences of mean in fundamental frequency between two age groups were significant (P = 0.007). Mean fundamental frequency analysis can discriminates between normal voice and voice with nodules only in 50 to 59-year age group. Although nodules were recognizable through stroboscope, acoustic signs varied depending on the amount of influence exerted by the nodule on the voice.