3-DIMENSIONAL REPRESENTATION OF EVOKED OT OACOUSTIC EMISSIONS

A new method for the transformation of TEOAE signals into 3-dimensiona l 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 firs t clinical study 390 TEOAE signals from ears with and without hearing impairment were evaluated. For normal hearing the 3-dimensional diagra m of TEOAE-signals is characterised by a typical wave form: with incre asing frequency the latency of the cochlear response decrease. In the case of hearing loss there is an overall tendency to increasing wave l atencies in comparison to normal hearing. An additional wave in the 3- dimensional diagrams of ears with tinnitus was observed. This characte ristic is interpreted as an indicator of cochlea dysfunction. The 3-di mensional diagram promises to give a new aspect in the clinical interp retation of click-evoked otoacoustic emissions.