Automatic screening and detection of threshold fine structure

Abstract

Audiograms measured with a high frequency resolution often show quasi-periodic ripples of up to 15 dB in normal-hearing listeners. This fine structure of the threshold in quiet is commonly associated with the active processes in the cochlea. Therefore its absence is discussed in the literature as an indicator of cochlear vulnerability. In order to enable a quick detection and an objective quantification of threshold fine structure, two instruments are introduced and evaluated in this article: a high-resolution tracking method for measuring fine structure ("FI-NESS") and an automatic fine-structure detector ("FINESS-detector"). The method is tested on 22 subjects for its reliability, its accuracy and drifts with frequency by analysing test/retest experiments and by comparing the measured thresholds to results from a reference procedure. The results indicate that FINESS and the FINESS-detector are suitable techniques for the measurement and detection of threshold fine structure that may help to investigate further into whether fine structure is a sensitive tool for the detection of an early hearing loss.

Spontaneous otoacoustic emissions, threshold microstructure, and psychophysical tuning over a wide frequency range in humans

“…In the past, most reports of threshold microstructure have been largely qualitative. Here, we employed a variation of the algorithm developed by Heise et al (2008) to quantify threshold microstructure characteristics. Briefly, each averaged threshold curve was linearly interpolated in 1 Hz steps using MATLAB.…”

Temporal integration near threshold fine structure–The role of cochlear processing

“…The stimulus frequencies were adjusted to match either a minimum ("valley condition") or a maximum ("peak condition") of the subjects individual threshold fine structure (see Fig.1). To determine individual peaks and valleys in threshold fine structure, the quiet threshold fine structure was screened in various octave bands, using a modified von Békésy tracking method as suggested by Heise et al (2008), until a region showing sufficient fine structure was determined. A suitable pair of adjacent peak and valley was selected for each subject and used for the following experiments.…”

“…In regions of fine structure, the detection threshold of pure tones can change up to around 15 dB over a frequency range of typically one tenth of an octave (Heise et al, 2008). Minima in the fine structure often coincide with the center frequency of spontaneous otoacoustic emissions, suggesting a common underlying mechanism (Zwicker and Schloth, 1984).…”

A Nonlinear Transmission Line Model of the Cochlea With Temporal Integration Accounts for Duration Effects in Threshold Fine Structure

“…Before measuring thresholds as afunction of stimulus duration, the individual fine structure wasmeasured in various octave bands until ar egion showing sufficient fines tructure wasdetermined for each subject. As ascreening procedure, the modified vonB ékésy tracking method of [2] wasused. Adjacent peak and trough frequencies between 1and 3kHz were selected for each subject and used in the following temporal-integration experiments.…”

“…This is commonly referred to as microstructure [1] or fines tructure [2] of the threshold in quiet. Other psychoacoustical effects such as binaural diplacusis have been argued to be linked to this threshold finestructure [3].…”