NORMATIVE VALUES FOR POLISH  DICHOTIC DIGIT TEST

Senderski A (1), McPherson D (2), Kochanek K (1), Piotrowska A (1), Skarzynski H. (1)

(1) Institute of |Physiology and Pathology of Hearing Warsaw, Poland; (2) Brigham Young University  Provo, USA.

Dichotic listening tests are among the most powerful of the behavioral auditory processing test battery. They are used as a measure of interhemispheric transfer of information and development and maturation of the auditory nervous system.  The aim of the study was to develop the normative data for polish dichotic digits test in children. Material consisted of 6355 7 y.o.  and 5910 12 y.o. children with normal hearing sensitivity (threshold better than 15 dB HL for frequencies from 500 to 8000 Hz) without learning and language problems. The test was conducted in free recall mode (divided attention). Age-specific normal cutoffs were developed using the criterion of two standard deviations below the means. The results: Mean – 2SD values were as follow:  45% for right ear and 10 % for the left ear for 7 y.o. children and 70% for the right ear and 50% for the left ear in 12 y.o. children. We observed statistically significant right ear advantage (REA) in both groups of children. The REA was significantly greater in 7 y.o. children comparing to 12 y. o. children. The REA reflects left hemisphere dominance for language and it was present in our material regardless of handedness. The reduction of REA with age can be treated as an effect of the maturation of the auditory system. Further research on the Polish DDT is recommended to investigate its validity and reliability, and to study its performance on children with known auditory processing deficits.

E-mail: a.senderski@ifps.org.pl