Background and Aim: Preterm birth is one of the risk factors need comprehensive audiological assessment. In this study, the effect of sex and rate of stimulation on response of children with history of preterm birth was investigated by auditory brainstem response (ABR).

Methods: This cross-sectional study was conducted using convinience sampling. Click-evoked a uditory brainstem response test with both low (21.1 c/s) and high (51.1 c/s) stimulus rates was recorded in 30 children with a history of preterm birth and 30 ones with history of term labor, as controls.

Results: Significant differences were observed in inter-peak latencies of I-III in both rates, III-V in the low rate, I-V in the high rate, and absolute latency of III wave between high and low stimulus rates (p<0.05 for all). Rate of stimulus affect on auditory brainstem response of preterm birth group was more than controls. Sex also affected on some parameters of auditory brainstem response test.

Conclusion: Preterm birth group showed longer latencies than normal group in both rates. Rate of stimulus had significant effect on results of children with history of preterm birth compared normal group. These findings may reflect the negative effect of preterm birth on neural synchronization function in response to transient stimuli.

Background and Aim: In the process of assessing the nasalance scores in patient’s speech, it is vital to know about normative data in the speech of normal subjects. The main objective in this study was to obtain normative data on nasalance scores in normal Persian-speaking children aged 3.5 to 6.5 years.

Methods: In this cross-sectional and comparative study, nasalance was measured in the speech of 112 children (55 boys and 57 girls) in Tehran, Iran. After auditory screening and speech assessments, the subjects who get the sufficient criterions entered the study. Speech sample was obtained by imitation and repeating sentences (14 oral and 3 nasal sentences) and mean nasalance score was measured by Nasal view software.

Results: A mean nasalance score of 46.25% was obtained for nasal sentences and a mean score of 43.67% for fricative sentences, 43.41% for affricative sentences and 42.21% for stop sentences. There was higher nasalance scores in girls but the difference was not significant (p=0.201) there was a significant difference in nasalance scores between different age groups in stop (p=0.037), fricative (p=0.036) and nasal sentences (p=0.032).

Conclusion: Findings of this study prepared good statistical data about nasalance scores in normal Persian-speaking children aged 3.5-6.5 years. The study also revealed that nasalance scores can be different in sentences with same manner of articulation and can be affected by presence or absence of nasal consonants and even age.