Both ABP and ICP contribute independently to the spTMD signal, with most power occurring at clear physiological frequencies-respiration and harmonics and heart rate and harmonics. There is information shared between the ICP and spTMD that is not present in ABP. This analysis has indicated that lower frequencies appear to favour ICP as the driver for spTMD.

We present the largest dataset of evoked TMD in healthy individuals and the first set of RIs for V . A patient cohort with both invasive ICP and evoked TMD measurements is needed to validate the technique for clinical use.

Spontaneous otoacoustic emissions (SOAE) are sounds generated inside the living cochlea and are regarded as by-products of the active mechanism present in the peripheral auditory system. There is still debate whether these emissions are the product of local oscillators located at various positions along the cochlea (local oscillator model) or if they result from standing waves due to a global collective phenomenon that involves different aspects of the cochlea (global standing wave model). This paper uses a global standing wave cochlear model to predict various features of SOAEs. This involves a state-space formulation with a spatially distributed set of nonlinear active micromechanical elements coupled via cochlear fluid coupling. Simulation results have been compared with available experimental data and demonstrate two interesting nonlinear features of the cochlea: first, nonlinear properties of SOAEs modulated by external low-frequency bias tones are easily predicted and can be used to investigate the plausibility of different nonlinear functions incorporated in the micromechanical elements. Second, entrainment patterns can be obtained when the model is stimulated by a swept-tone: results show distinct areas of beating and others of entrainment between the external stimulus and the SOAE, which depend on the level and instantaneous frequency of the sweep.

Models of the mammalian cochlea have been proposed in a number of ways and they have varying degree of realism and complexity. The transmission-line (TL) models are faithful to the physiology, particularly in terms of cochlear nonlinearity, but are computationally demanding. The pole-zero filter cascade (PZFC) model, however, is much more efficient to implement, but the nonlinearity is included implicitly, using an automatic gain control network. In this study, the connection between the linear responses of these two models is first discussed, followed by a comparison of their nonlinear responses in terms of self-suppression and two-tone suppression on the level of the basilar membrane. Both models are capable of simulating dynamic range compression as measured on the cochlear partition, but the TL model is more reasonable in representing twotone suppression, with the PZFC having lower suppression thresholds and over-predicting the suppression due to high-side suppressors. Further tuning of its parameters and structure, especially the automatic gain control (AGC) network may be possible to make it more compatible with these experimental observations. After adapting the PZFC model to have a more realistic nonlinear behavior, its use for investigating auditory signal processing such as masking effects, and hence as a front-end processor for acoustic signals can be enhanced, while retaining its computational efficiency.

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