Tone-burst Otoacoustic Emissions Research Articles

Examining basilar membrane motion of an auditory model by using tone-burst otoacoustic emissions

Article Examining basilar membrane motion of an auditory model by using tone-burst otoacoustic emissions was published on September 6, 2012 in the journal Biomedical Engineering / Biomedizinische Technik (volume 57, issue SI-1-Track-O).

Objective estimation of loudness growth in hearing-impaired listeners

A methodology for the estimation of individual loudness growth functions using tone-burst otoacoustic emissions (TBOAEs) and tone-burst auditory brainstem responses (TBABRs) was proposed by Silva and Epstein [J. Acoust. Soc. Am. 127, 3629-3642 (2010)]. This work attempted to investigate the application of such technique to the more challenging cases of hearing-impaired listeners. The specific aims of this study were to (1) verify the accuracy of this technique with eight hearing-impaired listeners for 1- and 4-kHz tone-burst stimuli, (2) investigate the effect of residual noise levels from the TBABRs on the quality of the loudness growth estimation, and (3) provide a public dataset of physiological and psychoacoustical responses to a wide range of stimuli intensity. The results show that some of the physiological loudness growth estimates were within the mean-square-error range for standard psychoacoustical procedures, with closer agreement at 1 kHz. The median residual noise in the TBABRs was found to be related to the performance of the estimation, with some listeners showing strong improvements in the estimated loudness growth function when controlling for noise levels. This suggests that future studies using evoked potentials to estimate loudness growth should control for the estimated averaged residual noise levels of the TBABRs.

Analysis of parameters for the estimation of loudness from tone-burst otoacoustic emissions

There is evidence that tone-burst otoacoustic emissions (TBOAEs) might be useful for estimating loudness. However, within-listener comparisons between loudness and TBOAE measurements are an essential prerequisite to determine appropriate analysis parameters for loudness estimation from TBOAE measurements. The purpose of the present work was to collect TBOAE measurements and loudness estimates across a wide range of levels in the same listeners. Therefore, TBOAEs were recorded for 1- and 4-kHz stimuli and then analyzed using a wide range of parameters to determine which parameter set yielded the lowest mean-square-error estimation of loudness with respect to a psychoacoustical, cross-modality-matching procedure and the inflected exponential (INEX) loudness model. The present results show strong agreement between 1-kHz loudness estimates derived from TBOAEs and loudness estimated using cross-modality matching (CMM), with TBOAE estimation accounting for almost 90% of the CMM variance. Additionally, the results indicate that analysis parameters may vary within a reasonable range without compromising the results (i.e., the estimates exhibit some parametric robustness). The lack of adequate parametric optimization for TBOAEs at 4 kHz suggests that measurements at this frequency are strongly contaminated by ear-canal resonances, meaning that deriving loudness estimates from TBOAEs at this frequency is significantly more challenging than at 1 kHz.

Parameters for the estimation of loudness from tone‐burst otoacoustic emissions.

There is evidence that tone‐burst otoacoustic emissions (TBOAEs) might be useful for estimating loudness, but appropriate analysis parameters for loudness estimation must first be examined. The purpose of the present work was to collect TBOAE measurements and loudness estimates across a wide range of levels in the same listeners. Both measures were recorded for 1‐ and 4‐kHz stimuli and then analyzed using a wide range of parameters to determine which parameter set yielded lowest mean‐square‐error estimation of loudness with respect to a psychoacoustical, cross‐modality‐matching procedure and the inflected exponential (INEX) loudness model. The present results show strong agreement between 1‐kHz loudness estimates derived from TBOAEs and loudness estimated using cross‐modality matching, with TBOAE estimation accounting for a significant portion of the variance. Additionally, the results indicate that analysis parameters may vary within a reasonable range without compromising the results (i.e., the estimates exhibit some parametric robustness). The lack of adequate parametric optimization for TBOAEs at 4 kHz suggests that measurements at this frequency are strongly contaminated by the ear‐canal resonances, meaning that deriving loudness estimates from TBOAEs at this frequency is significantly more challenging than at 1 kHz. [Work supported by Capita Foundation.]

Tone burst-evoked otoacoustic emissions in neonates: normative data

BackgroundTone-burst otoacoustic emissions (TBOAEs) have not been routinely studied in pediatric populations, although tone burst stimuli have greater frequency specificity compared with click sound stimuli. The present study aimed (1) to determine an appropriate stimulus level for neonatal TBOAE measurements when the stimulus center frequency was 1 kHz, (2) to explore the characteristics of 1 kHz TBOAEs in a neonatal population.MethodsA total of 395 normal neonates (745 ears) were recruited. The study consisted of two parts, reflecting the two study aims. Part I included 40 normal neonatal ears, and TBOAE measurement was performed at five stimulus levels in the range 60–80 dB peSPL, with 5 dB incremental steps. Part II investigated the characteristics of the 1 kHz TBOAE response in a large group of 705 neonatal ears, and provided clinical reference criteria based on these characteristics.ResultsThe study provided a series of reference parameters for 1 kHz TBOAE measurement in neonates. Based on the results, a suggested stimulus level and reference criteria for 1 kHz TBOAE measures with neonates were established. In addition, time-frequency analysis of the data gave new insight into the energy distribution of the neonatal TBOAE response.ConclusionTBOAE measures may be a useful method for investigating cochlear function at specific frequency ranges in neonates. However, further studies of both TBOAE time-frequency analysis and measurements in newborns are needed.

Tone-burst otoacoustic emissions and loudness

Several models of cochlear mechanics lead to the conclusion that the amplitude of tone-burst otoacoustic emissions (TBOAEs) is proportional to basilar-membrane (BM) motion. Buus and Florentine [Fechner Day 2001 (Pabst, Berlin), 236 (2001)] showed that the square of loudness, derived from measurements of spectral and temporal integration, closely matched basilar-membrane velocity at the best frequency. Buus et al. [Physiological and Psychophysical Bases of Auditory Function, 373 (2001)] examined the relationship between distortion-product otoacoustic emissions (DPOAEs) and BM motion. Follow-up work by Epstein et al. [J. Acoust. Soc. Am. 117, 263 (2005)] showed in a direct comparison that TBOAEs and psychoacoustical measures, of loudness and of pulsation threshold, on six subjects with normal hearing led to very similar estimations of basilar-membrane motion. These outcomes suggest that otoacoustic emissions could serve as an excellent tool–one that is objective, non-invasive, and rapid–for estimating in subjects with normal hearing both relative basilar-membrane motion and relative loudness. [Work supported by NIH/NIDCD Grant R01DC02241.]

Inferring basilar-membrane motion from tone-burst otoacoustic emissions and psychoacoustic measurements

The amplitude of otoacoustic emissions, which arise on the basilar membrane, is assumed to be proportional to basilar-membrane motion. It should then be possible to assess basilar-membrane motion on the basis of otoacoustic emissions. The present study provides support for this possibility by comparing basilar-membrane motion inferred from emissions to that inferred from psychoacoustic measures. Three psychoacoustic measurements believed to be associated with basilar-membrane motion were investigated: (1) pulsation threshold; (2) loudness functions derived from temporal integration; and (3) loudness functions derived from loudness matches between pure tones and multitone complexes. Results of the psychoacoustic measurements and of the tone-burst otoacoustic emissions led to very similar estimations of basilar-membrane motion. Accordingly, emissions could serve as an excellent tool--one that is objective, noninvasive, and rapid--for estimating relative basilar-membrane motion.

The effects of window delay, delinearization, and frequency on tone-burst otoacoustic emission input/output measurements.

Tone-burst otoacoustic emissions (TBOAEs) are a potential tool for objectively examining cochlear activity in humans. However, their use requires knowledge of how the TBOAE input/output depends on measurement and analysis paradigms. The present experiment examined the effect of variations in response-window timing, response delinearization, and local changes in stimulus frequency on TBOAE input/output measurement. None of these experimental manipulations had a profound effect on TBOAE measurements as long as reasonable parameter choices were made. Nonetheless, judicial choice of the experimental parameters can optimize the assessment of BM I/O functions. It is concluded that the consistency of TBOAE I/O across the parameters tested makes it a viable tool to consider for examining human cochlear activity.

Can tone-burst otoacoustic emissions be used to measure basilar-membrane response in humans?

Tone-burst otoacoustic emissions (TBOAEs) are a potential tool for examining basilar-membrane activity in humans. However, their use requires knowledge of just how the relation between TBOAEs and basilar-membrane input-output (BM I/O) activity depends on measurement and analysis parameters. The present experiment examined three such parameters: (1) response-window timing, (2) response delinearization, and (3) stimulus frequency. Varying the onset of the post-stimulus-recording analysis window had little effect on the function relating emission amplitude to SPL. Response delinearization, if anything, tended to obscure the relation between TBOAE and stimulus level. Changes in stimulus frequency over a range of 1 Bark had no effect on TBOAE amplitude. Although none of these experimental manipulations had a significant effect on TBOAE measurements, a judicial choice of the experimental parameters can optimize the assessment of BM I/O functions. It is concluded that TBOAEs provide a useful tool for objective BM I/O function analysis in humans. [Work supported by NIH-NIDCD Grant R01DC00187.]