[The influence of conductive hearing loss on DPOAE-threshold. The effect of an individually optimized stimulation].

BACKGROUND

The DPOAE-threshold, estimated from extrapolated I/O functions, allows an objective assessment of the mechanical sensitivity of the inner ear. In children, the specificity of this diagnostic tool is impaired by conductive hearing loss.

METHODS

In this study, we propose an individual optimization of the primary tone level ratio. This procedure allows the detection of a conductive hearing loss that can be accounted for when estimating the DPOAE-threshold. By means of a simulation using DPOAE-data from 22 normally hearing subjects, the effects of this procedure on the estimation of the DPOAE-threshold are examined.

RESULTS

An individually optimized DPOAE stimulation distinctly improves the signal-to-noise ratio of the DPOAE which enables an estimation of the DPOAE-threshold for sound conductive losses up to 15 dB. The DPOAE-threshold only worsens in individual cases.

CONCLUSIONS

An individually optimized stimulation paradigm may improve the specificity of inner ear diagnostics with the DPOAE-threshold. A clinical evaluation of the method in children, however, is necessary.