Development and application of a /bAk/-/dAk/ continuum for testing auditory perception within the Dutch longitudinal dyslexia study

A national longitudinal research program on developmental dyslexia was started in The Netherlands, including auditory perception and processing as an important research component. New test materials had to be developed, to be used for measuring the auditory sensitivity of the subjects to speech-like stimuli from birth until the age of 10 years. This paper describes the subsequent steps and experiments in developing the auditory test material. Several experiments showed that dyslexic adults, as compared to a control group, were less accurate and slower in discriminating phoneme contrasts with subtle acoustic differences. The continuum developed so far, was tested in an experiment using a mismatch negativity paradigm applied in an adult control group. Results of this ERP study indicated that reliable mismatch negativity could be obtained which warrants the application of the paradigm and the stimuli to be appropriate for the currently running Dutch longitudinal dyslexia study.