[Investigation of Persian speech interaural attenuation in adults]

ABSTRACT

As clinical audiometry assessment of each ear needs to know interaural attenutation [IA], the aim of this study was to investigate Persian speech IA in adults. This cross-sectional, analytic study was performed on 50 normal hearing students [25 males, 25 females], aged 18-25 years old in Faculty of Rehabilitation, Tehran University of Medical Sciences. Speech reception threshold [SRT] was determined with descending method with and without noise. Then speech IA for Persian spondaic words was calculated with TDH-39 earphones. Mean speech IA was 53.06 +/- 3.25 dB. There was no significant difference between mean IA in males [53.88 +/- 2.93 dB] and females [52.24 +/- 3.40 dB] [p>0.05]. The lowest IA was in females [45dB] and the highest IA was in males [60 dB]. Mother's language has no significant effect on speech IA. We may consider 45 dB as the lowest IA for Persian speech assessment, however generalization needs more study on a larger samples