Estimation of Minor Conductive Hearing Loss in Humans Using Distortion Product Otoacoustic Emissions

Abstract

This study provides empirical support for a theory of how CHL, through a combination of middle ear filtering and alteration of effective primary tone level relationships within the cochlea, systematically affects DPOAE amplitude. Although CHLDP was shown to be significantly predictive of CHLPT when optimization formula parameters for a given ear, both with and without mild CHL, were known, the lack of a meaningful relationship when using generic primary tone level formula parameters significantly limits the method's potential for clinical utility.

Subclinical conductive hearing loss significantly reduces otoacoustic emission amplitude: Implications for test performance

“…The influence of conductive hearing loss on DPOAE generation and measurement can be modeled as if occurring via 3 primary mechanisms [16]. First, CHL reduces the effective levels of the primary tones within the cochlea.…”

“…Third, CHL attenuates the level of the generated DPOAE as it is transmitted towards the ear canal. The amount of this attenuation has previously been assumed to be equal to the attenuation of the primary tones within the forward pathway [13,16]. These 3 mechanisms combine to produce a total attenuation of DPOAE amplitude which is in excess of the nominal CHL magnitude, a characteristic which helps explain the potentially outsized impact of even minor CHL on clinical DPOAE results, as well as highlight the importance of precisely evaluating CHL in individual ears.…”

“…Specifically, DPOAEs have shown utility as an objective means of identifying normal and hearing impaired ears, such as for use in newborn hearing screening programs or evaluating other difficult-to-test populations [3][4][5][6], estimating hearing threshold [7][8][9][10], differentiating sensorineural and conductive hearing loss (CHL) [10][11][12], objectively quantifying conductive hearing loss [13][14][15][16], differentiating cochlear and neural pathology for the diagnosis of auditory neuropathy/synaptopathy [17], and monitoring for deleterious side-effects of ototoxic medications [18,19]. Unfortunately, as many otologic conditions prevalent in childhood are characterized by CHL [20][21][22][23] and because CHL can significantly impair interpretation of DPOAE results [24][25][26][27], the full clinical utility of DPOAEs often goes unrealized in pediatric cases.…”

Preservation of Distortion Product Otoacoustic Emissions in OTOF-Related Hearing Impairment

“…Specifically, the question of the coexistence of transient OAE loss with conductive hearing impairment due to otitis media with effusion (OME) has not been addressed. OME, which occurs with high frequency in children aged 1 to 4 years, impacts on the amplitude of OAEs recorded in the ear canal, eventually leading to OAEs disappearance ( Marcrum et al 2017 ). Consequently, the presence of OAEs responses could have been overlooked in some children in the presence of middle ear dysfunction due to tympanic membrane retraction or middle ear effusion.…”