Weighted DPOAE Input/Output-functions: A tool for automatic assessment of hearing loss in clinical application

Johnson²,

Kopun³

et al. 2009

Distortion-product otoacoustic emission ͑DPOAE͒ input/output ͑I/O͒ functions were measured in 322 ears of 176 subjects at as many as 8 f 2 frequencies per ear for a total of 1779 I/O functions. The f 2 frequencies ranged from 0.7 to 8 kHz in half-octave steps. Behavioral thresholds ͑BTs͒ at the f 2 frequencies ranged from Ϫ5 to 60 dB hearing loss ͑HL͒. Both linear-pressure and nonlinear, two-slope functions were fitted to the data. The two-slope function describes I/O compression as output-controlled self-suppression. Most I/O functions ͑96%͒ were better fitted by the two-slope method. DPOAE thresholds based on each method were used to predict BTs. Compared to estimates based on linear-pressure functions, individual BTs predicted from DPOAE thresholds based on the two-slope model had lower residual error and accounted for more variance. Another advantage of the two-slope method is that it provides an estimate of response growth rate ͑RGR͒ that is not tied to threshold. At all frequencies, the median low-level RGR ͑across I/O functions of the same f 2 and BT͒ usually increased as BT increased, while high-level compression decreased. The observed characteristics of DPOAE I/O functions are consistent with the loss of cochlear compression that is typically associated with mild-to-moderate HL.

Section: B Analysismentioning

confidence: 99%

Distortion-product otoacoustic emission input/output characteristics in normal-hearing and hearing-impaired human ears

Johnson²,

Kopun³

et al. 2009

“…With hearing loss, the DPOAE I/O function becomes steeper, less compressive (more linear) and has a reduced range over which compression takes place (e.g., Dorn et al, 2001). The relation between degree of hearing loss, as measured using audiometric thresholds, and DPOAE level has been demonstrated in several studies (e.g., Boege and Janssen, 2002;Gorga et al, 2003;Oswald and Janssen, 2003;Rogers et al, 2010). As a consequence of the relationship between DPOAEs and hearing loss, DPOAEs have been used as objective non-invasive probes of cochlear status (e.g., Gorga et al, 1997), and are currently used in many newborn-hearingscreening programs.…”

Section: Introductionmentioning

confidence: 96%

Relation of distortion-product otoacoustic emission input-output functions to loudness

Rasetshwane

Kopun

et al. 2013

The aim of this study is to further explore the relationship between distortion-product otoacoustic emission (DPOAE) measurements and categorical loudness scaling (CLS) measurements using multiple linear regression (MLR) analysis. Recently, Thorson et al. [J. Acoust. Soc. Am. 131, 1282-1295] obtained predictions of CLS loudness ratings from DPOAE input/output (I/O) functions using MLR analysis. The present study extends that work by (1) considering two different (and potentially improved) MLR models, one for predicting loudness rating at specified input level and the other for predicting the input level for each loudness category and (2) validating the new models' predictions using an independent set of data. Strong correlations were obtained between predicted and measured data during the validation process with overall root-mean-square errors in the range 10.43-16.78 dB for the prediction of CLS input level, supporting the view that DPOAE I/O measurements can predict CLS loudness ratings and input levels, and thus may be useful for fitting hearing aids.

“…Additionally, the frequencies at which maxima and minima occur within an individual ear may shift as level is increased (e.g., Schmiedt, 1993, 1997;Heitmann et al, 1996;Johnson et al, 2006b). This shift will influence the slope of the DPOAE I/O function and, therefore, may not only affect predictions of auditory status (i.e., normal versus impaired), but also may affect the accuracy with which behavioral thresholds can be predicted from DPOAE I/O functions (e.g., Boege and Janssen, 2002;Gorga et al, 2003;Oswald and Janssen, 2003). Indeed, report less variability in thresholds predicted from DPOAE I/O functions across frequency when the reflection-source contribution was reduced or eliminated, although they do not describe the correspondence between these predicted thresholds and measured behavioral thresholds.…”

Section: Introductionmentioning

confidence: 99%

Distortion product otoacoustic emissions: Cochlear-source contributions and clinical test performance

Johnson

Kopun

et al. 2007

It has been proposed that the clinical accuracy of distortion product otoacoustic emissions (DPOAEs) is affected by the interaction of distortion and reflection sources contributing to the response. This study evaluated changes in dichotomous-decision test performance and threshold-prediction accuracy when DPOAE source contribution was controlled. Data were obtained from 205 normal and impaired ears with L 2 ranging from 0 to 80 dB SPL and f 2 = 2 and 4 kHz. Data were collected for control conditions (no suppressor, f 3 ) and with f 3 presented at 3 levels that previously had been shown to reduce the reflection-source contribution. The results indicated that controlling source contribution with a suppressor did not improve diagnostic accuracy (as reflected by ROC curve area) and frequently resulted in poorer test performance compared to control conditions. Likewise, correlations between DPOAE and behavioral thresholds were not strengthened when using the suppressors to control source contribution. While improvements in test accuracy were observed for a subset of subjects (normal ears with the smallest DPOAEs and impaired ears with the largest DPOAEs), the lack of improvement for the larger, unselected subject group suggests that DPOAEs should be recorded in the clinic without attempting to control the source contribution with a suppressor.