3-DIMENSIONAL REPRESENTATION OF EVOKED OTOACOUSTIC EMISSIONS

A new method for the transformation of TEOAE signals into 3-dimensional diagrams is presented. The special transformation algorithm is based on a latency related frequency analysis of the cochlear response. The analysis and presentation are implemented in a C-programme. In a first clinical study 390 TEOAE signals from ears with and without hearing impairment were evaluated. For normal hearing the 3-dimensional diagram of TEOAE-signals is characterised by a typical wave form: with increasing frequency the latency of the cochlear response decrease. In the case of hearing loss there is an overall tendency to increasing wave latencies in comparison to normal hearing. An additional wave in the 3-dimensional diagrams of ears with tinnitus was observed. This characteristic is interpreted as an indicator of cochlea dysfunction. The 3-dimensional diagram promises to give a new aspect in the clinical interpretation of click-evoked otoacoustic emissions.