Determination of appropriate compression rate for developing the Persian version of time compressed sentence test

Time compressed speech test is one of the most useful monaural tests for evaluation of central auditory processing disorder. For developing the time compressed sentences test, the compression rate of the sentences must be set so that the average speech comprehension score is about 90% in normal individuals and can challenge central auditory processing system sufficiently so subjects with auditory processing disorders could be identified. Therefore, the aim of the present study was finding the appropriate compression rate for developing compressed sentences test in Persian. Initially, two 10-sentence lists were prepared based on the experts’ opinion and were compressed by the amount of 60, 65, 70, 75 and 80% using Praat software. Compressed sentences were tested on twelve 18–25 year-old normal individuals and the speech comprehension score in different compression rates was compared and the compression rate in which the average score was approximately 90% was reported as an appropriate compression rate for developing time compressed sentences test in Persian. 70% compression rate was able to create an average score of 95.27% (± 3.31) and 93.6% (± 7.17) in the right and left ear, respectively. Results showed that the compre ssion rate of 70% was appropriate rate for developing the test in the Persian language.