A. Szkiełkowska, J Ratyńska, M. Kurkowski, A. Senderski, H Skarżyński, R. Markowska “Coherence between Tomatis test and central auditory processing audiologic tests battery in children with dyslexia” .
Dyslexia is a specific , language-based disorder, which characterises by the difficulty id words decoding, which reflects insufficient abilities of phonologic processing. Develpmental dyslexia, according to different authors, affects from 4% to 12% of school age population and is characterized by the difficulty in reading in a child with normal hearing and intelligence. Reading is a complex ability, which requires cooperation of different functions. Several studies have shown that dyslexia may be accompanied by auditory processing disturbances, such as disturbance of phonematic hearing, difficulty in sound analysis and pitch discrimination . There is no consensus whether presented auditory difficulties are related specifically with speech sounds or generally to all kinds of sound stimuli. Some theories suggest that processing disturbances affect also visual modality. The aim of the study was to evaluate time and frequency processing in children with developmental dyslexia. Material and methods The studied group were 20 children aged from 10 y.o to 14 y.o. diagnosed with confirmed dyslexia. The control group was formed by 20 children without school problems. All children have been examined by otolaryngologist and have had hearing tests performed, including pure tone audiometry and impedance audiometry. All children have been assessed by speech therapist and psychologist in order to confirm existing difficulties and to assess intelligence scores. In the studied group lowered scores of speech sound analysis and synthesis have been found. For psychological evaluation Benton, Rey and Wechsler tests have been used. All children in the studied group had normal intelligence scores , no vision defects and normal hearing thresholds. All children were right – handed. Auditory functions have been assessed with the use of Duration Pattern Test (DPD) developed by Musiek and Frequency Pattern Test (FTP) by Pinheiro. In the existing literature temporal analysis in children with dyslexia was assessed with battery of tests called temporal order judgement (TOJ). DPT and FPT tests can assess temporal aspects of sound analysis . Stimuli are presented separately to each ear at the level of 50 dB SL. Tests were performed in sound booth. In both tests, 30 sequences of 3 tones were presented. In DPT test 3 tones of 250ms and 500 ms are presented. In FPT tones of 1122 Hz and 880 Hz are presented. The child is expected to give answer reegarding pitch of the tone sequence (eg. High pitch, low pitch, high pitch) or tone duration(eg long – short – long). Scores below 80% for each test were considered as below normal. All children were tested as well with the use of Tomatis procedure, in order to assess auditory attention to external and internal sounds, pitch discrimination and auditory laterality. The results were subjected to statistical analysis with the use of t-Student test. Statistical analysis revealed significance level p<0.05 between the studied and control groups. Results In 18 children (90%) with dyslexia results in DPT and PPT were abnormal. 2 children had normal scores both on DPT and FPT. In the studied group, mean value for DPT in the right ear was 46,4% and in the left ear 42,6% of correct answers. In the control group, corresponding values were 95,4% and 96,7%.