Auditory recognition of Persian digits in presence of speech-spectrum noise and multi-talker babble: a validation study

Background and Aim: Digits are suitable speech materials for evaluating recognition of speech-in-noise in clients with the wide range of language abilities. Farsi Auditory Recognition of Digit-in-Noise (FARDIN) test has been deve-loped and validated in learning-disabled child-ren showing dichotic listening deficit. This stu-dy was conducted for further validation of FARDIN and to survey the effects of noise type on the recognition performance in individuals with sensory-neural hearing impairment. Methods: Persian monosyllabic digits 1−10 were extracted from the audio file of FARDIN test. Ten lists were compiled using a random order of the triplets. The first five lists were mixed with multi-talker babble noise (MTBN) and the second five lists with speech-spectrum noise (SSN). Signal- to- noise ratio (SNR) var-ied from +5 to −15 in 5 dB steps. 20 normal hearing and 19 hearing-impaired individuals participated in the current study. Results: Both types of noise could differentiate the hearing loss from normal hearing. Hearing-impaired group showed weaker performance for digit recognition in MTBN and SSN and needed 4−5.6 dB higher SNR (50%), compared to the normal hearing group. MTBN was more challenging for normal hearing than SSN. Conclusion: Farsi Auditory Recognition of Digit-in-Noise is a validated test for estimating SNR (50%) in clients with hearing loss. It seems SSN is more appropriate for using as a back-ground noise for testing the performance of aud-itory recognition of digit-in-noise.