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.
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.