Research Article

Persian randomized dichotic digits test: Development and dichotic listening performance in young adults


Background and Aims: The dichotic listening subtest is considered as an important component of the test battery for auditory processing assessment in both children and adults. A randomized dichotic digits test (RDDT) was created to compensate for sensitivity weakness of double digits when detecting abnormal ear asymmetry during dichotic listening. The aim of this study was the development and initial evaluation of the Persian randomized dichotic digits test.
Method: Persian digits 1-10 (except for the bisyllabic digit, 4) uttered by a native Persian language speaker were recorded in a studio. After alignment of intensity and temporal characteristics of digit waveforms, lists 1 and 2 of the RDDT were reproduced. List 1 of the test was administered at 55 dBHL on 50 right-handed normal hearing individuals (with an equal sex ratio) in the age group of 18-25 years and hearing thresholds of 15 dBHL or better in audiometric frequencies.
Results: Mean (standard deviation) percent-correct score for right and left ears and right ear advantage of the subjects was 94.3 (5.3), 84.8 (7.7), and 9.5 (7.0) percent, respectively. Sixty percent of the subjects showed normal results and unilateral and bilateral deficits were seen in 24 percent and 16 percent, respectively.
Conclusion: It seems the Persian version of RDDT is the same as the original test as it is able to test ear asymmetry, unilateral and bilateral deficits in dichotic listening.

1. Keith RW, Katbamna B, Tawfik S, Smolak LH. The effect of linguistic background on staggered spondaic word and dichotic consonant vowel scores. Br J Audiol. 1987;21(1):21-6.
2. Noffsinger D, Martinez CD, Wilson RH. Dichotic listening to speech: background and preliminary data for digits, sentences, and nonsense syllables. J Am Acad Audiol. 1994;5(4):248-54.
3. Strouse A, Wilson RH, Brush N. Recognition of dichotic digits under pre-cued and post-cued response conditions in young and elderly listeners. Br J Audiol. 2000;34(3):141-51.
4. Keith RW, Anderson J. Dichotic listening tests. In: Musiek FE, Chermak GD, editors. Handbook of (central) auditory processing disorder. Vol.1. 1st ed. San Diego: plural publishing; 2007. p. 207-30.
5. Strouse A, Wilson RH. Stimulus length uncertainty with dichotic digit recognition. J Am Acad Audiol. 1999;10(4):219-29.
6. Musiek FE, Gollegly KM, Kibbe KS, Verkest-Lenz SB. Proposed screening test for central auditory disorders: follow-up on the dichotic digits test. Am J Otol. 1991;12(2):109-13.
7. Bergendal G, Martola J, Stawiarz L, Kristoffersen-Wiberg M, Fredrikson S, Almkvist O. Callosal atrophy in multiple sclerosis is related to cognitive speed. Acta Neurol Scand. 2013;127(4):281-9.
8. Moncrieff DW, Musiek FE. Interaural asymmetries revealed by dichotic listening tests in normal and dyslexic children. J Am Acad Audiol. 2002;13(8):428-37.
9. Moncrieff DW, Wilson RH. Recognition of randomly presented one-, two-, and three-pair dichotic digits by children and young adults. J Am Acad Audiol. 2009;20(1):58-70.
10. Weihing JA, Musiek F. Dichotic Interaural Intensity Difference (DIID) training. In: Geffner D, Ross-Swain D, editors. Auditory processing disorders: assessment, management and treatment. 1st ed. San Diego: Plural Publishing Inc; 2007. p. 281-301.
11. Strouse A, Wilson RH. Recognition of one-, two-, and three-pair dichotic digits under free and directed recall. J Am Acad Audiol. 1999;10(10):557-71.
12. Mukari SZ, Keith RW, Tharpe AM, Johnson CD. Development and standardization of single and double dichotic digit test in the Malay language. Int J Audiol. 2006;45(6):344-52.
13. Chapman LJ, Chapman JP. The measurement of handedness. Brain Cogn. 1987;6(2):175-83.
14. Studebaker G. A "rationalized" arcsine transformation. J Speech Hear Res. 1985;28(3):455-62.
15. Jerger J, Chmiel R, Allen J, Wilson A. Effects of age and gender on dichotic sentence identification. Ear Hear. 1994;15(4):274-86.
16. Strouse A, Wilson RH, Brush N. Effect of order bias on the recognition of dichotic digits in young and elderly listeners. Audiology. 2000;39(2):93-101.
17. Studebaker GA, McDaniel DM, Sherbecoe RL. Evaluating relative speech recognition performance using the proficiency factor and rationalized arcsine differences. J Am Acad Audiol. 1995;6(2):173-82.
18. Wilson RH, Jaffe MS. Interactions of age, ear, and stimulus complexity on dichotic digit recognition. J Am Acad Audiol. 1996;7(5):358-64.
19. Voyer D. Sex differences in dichotic listening. Brain Cogn. 2011;76(2):245-55.
20. Jerger J, Martin J. Hemispheric asymmetry of the right ear advantage in dichotic listening. Hear Res. 2004;198(1-2):125-36.
21. Maerlender AC, Wallis DJ, Isquith PK. Psychometric and behavioral measures of central auditory function: the relationship between dichotic listening and digit span tasks. Child Neuropsychol. 2004;10(4):318-27.
IssueVol 23 No 6 (2015) QRcode
SectionResearch Article(s)
Dichotic listening adults ear advantage gender Persian language

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How to Cite
Mahdavi ME, Aghazadeh J, Tahaei SAA, Heiran F, Akbarzadeh Baghban A. Persian randomized dichotic digits test: Development and dichotic listening performance in young adults. Aud Vestib Res. 2017;23(6):99-113.