Development of the Farsi Hearing in Noise Test

Objectives: Develop sentences in Farsi for use in the Hearing In Noise Test (HINT); equalise the difficulty of the sentences; form twelve 20-sentence lists; and determine the reliability and norms for these materials. Design: The same study design as used in the development of HINT in other languages was followed. Sentences were sampled from elementary school reading materials. Sentence difficulty was matched by scaling sentence levels. Equivalent sentence lists were formed. Speech reception thresholds were measured under headphones in quiet and in three noise conditions that differed in the spatial locations of the speech and noise sources. Spatial locations were simulated using head-related transfer functions. Study sample: Subjects were 24 adult native speakers of Farsi with pure-tone thresholds <= 25 dB HL at audiometric frequencies from 0.25 to 8.00 kHz. Results: Reliability, the variability of test-retest score differences, was 1.28 dB in quiet and 1.08 dB in noise. Average speech reception thresholds in Quiet = 19.4 dB(A). Average signal/noise ratios at threshold were Noise Front = -5.4 dB, Noise Right = -13.7 dB, and Noise Left = -13.7. Conclusions: The reliability and norms for the Farsi HINT are comparable to those for other languages, enabling comparison of test results across languages.