Smoothing factor and voice perturbation measurements.

OBJECTIVE: Although gradual frequency and amplitude variations originating from intonation or vocal instability are not related to voice quality, jitter and shimmer are sensitive to such variations. These parameters are therefore calculated by subtracting the average of a group of successive periods from the middle period; the period number that is averaged is called the smoothing factor. The aim of this study was to investigate the effect of smoothing factor size on frequency and amplitude perturbation measurements. METHODOLOGY: A prospective study was designed, incorporating recorded voice samples from ten male and ten female healthy adult volunteers; samples were analyzed with the Multi Dimensional Voice Program for Multi-Speech. We used all low smoothing factor sizes up to 21, and then skipped smoothing factor sizes in steps of ten, resulting in 28 different levels. RESULTS: Smoothed pitch perturbation quotient and smoothed amplitude perturbation quotient values increased as the smoothing factor size increased. Smoothing factor size was correlated with smoothed pitch perturbation quotient and smoothed amplitude perturbation quotient values in males (r = 0.589 and r = 0.698, respectively) and females (r = 0.736 and r = 0.847, respectively). CONCLUSION: Our study revealed an exact relationship between smoothing factor values and perturbation measures. At low smoothing factor values, perturbation measures are sensitive to short-term variations, whereas at high smoothing factor values, they are less sensitive to short-term but more sensitive to long-term variations.

Horner's syndrome from giant schwannoma of the cervical sympathetic chain: case report.

OBJECTIVES: Nerve sheath tumours are uncommon lesions in adults. Schwannomas originating from the cervical sympathetic chain are a rare subgroup of nerve sheath tumours. Moreover, the existence of Horner's Syndrome before surgery is uncommon, with only five cases reported in the literature. Here we review the presentation, imaging characteristics, and operative considerations of a patient with a large cervical sympathetic chain schwannoma, presenting with Horner's Syndrome. A 60-year-old woman with a left upper eyelid ptosis presented to our outpatient department complaining of a painless left-sided neck mass. RESULTS: Histopathologic examination of excised mass, which was nearly 9.0 cm x 7.0 cm x 6.0 cm, revealed a benign schwannoma. CONCLUSION: When dealing with cervical masses, schwannoma should be considered in the differential diagnosis, especially when some neurological symptoms exist.

The effect of the speaker gender on speech intelligibility in normal-hearing subjects with simulated high frequency hearing loss.

OBJECTIVE: To determine whether speaker gender affects speech discrimination scores, in normal hearing and simulated high frequency hearing loss situations. MATERIALS AND METHODS: Listeners were twenty normal volunteers. The speech stimuli were eight phonetically balanced monosyllabic word lists, uttered by a male and a female speakers. These lists were low-pass filtered at 1500, 2500 and 3500 Hz's to represent high frequency hearing loss. To obtain speech discrimination scores, the subjects listened to each of the eight lists in a different filtering and talker conditions in a randomized order. For statistical analysis, Mann-Whitney U test was used. RESULTS: In normal hearing situation, the scores obtained by male and female speeches, were similar (p=0.60). On the contrary, statistically significant differences were observed in all of the three high frequency hearing loss situations (p<0.01). CONCLUSION: Female speech is significantly more difficult to discriminate than male speech in normal-hearing subjects with simulated high frequency hearing loss and probably in patients with high frequency hearing loss.