PP1307 - Can Otoacoustic Emissions Help to Evaluate Middle-Ear Status

Posters

Location: Halls 4EF

Lead Presenter(s)

Bella Brown-Quigley, BS (she/her/hers)

2nd Year Audiology Doctoral Student
California State University, Sacramento
California State University, Sacramento, California

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.

Presenter(s)

Soumya Venkitakrishnan, AuD, PhD

Assistant Professor
California State University, Sacramento
California State University, Sacramento
Sacramento, California

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.
Hamid Motallebzadeh, PhD (he/him/his)

Assistant Professor
California State University, Sacramento
California State University, Sacramento
Sacramento, California

Financial Disclosures: I do not have any relevant financial relationships with anything to disclose.
Non-Financial Disclosures: I do not have any relevant non-financial relationships with anything to disclose.

Abstract:

In otoacoustic emissions (OAEs) measurements, acoustic stimuli presented at the ear canal (EC) travel through the middle ear (ME) in forward direction to the cochlea. The sound generated inside the cochlea traverses the ME in the reverse direction and are measured in the EC. Thus, OAEs contain information about both the cochlea and ME. Wideband tympanometry (WBT) can measure impedance and provide information about the ME status. Since both these measures evaluate the middle ear function, the goal of this project is to determine the correlation between OAEs and WBT and to determine whether OAEs can assess the ME status.

Summary:

Background: Otoacoustic emissions (OAEs) are very faint sounds that are emitted by a healthy inner ear. Presence of OAEs is an indicator of cochlear health. In OAE measurements, acoustic stimuli presented at the ear canal (EC) travels through the middle ear (ME) in forward direction to the cochlea. Inside the cochlea, complex electro-mechanical processes generate sound that traverses the ME in the reverse direction and are measured in the EC. Thus, OAEs contain information about both the cochlear and the ME status. The ME status can also be assessed by tympanometry, a physiological measure of the ME impedance (or mobility). In contrast to the conventional pure-tone tympanometry, wideband tympanometry (WBT) provides information of the ME status in a wide frequency range. Though OAEs also provide an indirect measure of ME status, there are very limited (and only animal model) studies on the effect of the middle-ear abnormalities on the OAEs (e.g., Akinpelu et al., 2015; Qin et al., 2010). In a recent study (Motallebzadeh and Puria 2021 and 2022) we implemented a computational model to explicitly quantify the relationships between OAE measurements and the ME pressure gains in mouse, especially as related to changes in the material parameters of the ME.

Methods: This study includes two computational and clinical components. We utilize our previous computational models of the human middle ear and cochlea (Liang et al., 2022) and manipulate the ME parameters to measure the ME impedance and reflectance for normal and pathological conditions. We also plan to investigate the normal and pathological WBT and OAE responses from clinical data obtained in the Maryjane Rees Language, Speech & Hearing Center- Audiology Clinic at California State University, Sacramento using the Interacoustics Titan and reported data in the literature.

Results: The computational model provides wideband impedance and absorbance of both normal and pathological ME conditions. The model was validated against data reported in the literature. The variations of the ME parameters show measurable OAE variations in the EC. The next step is to map the variations of the OAEs to that of the WBT due to the alteration of the ME parameters. Because the ME round-trip transfer function is not accessible in clinical data, we plan to explore the effect of the ME status on the forward transfer functions (i.e., impedance and absorbance) and OAEs.

Conclusion: Mining complex patterns of the OAE responses for reliable indicators of ME condition has been proven to be both valuable and challenging. In this study, we explore two computational and clinical approaches to associate the OAE variations due to the ME abnormalities. Quantitative correlations of OAE variations due to the ME status, particularly for transient conductive pathology in newborns, can potentially reduce high false-positive rates in newborn hearing screenings.
This work was supported in part by National Institute on Deafness and Other Communication Disorders (NIDCD) Grant R21 DC020274 (to HM).

Learning Objectives:

Upon completion, participants will be able to examine the usefulness of otoacoustic emissions to assess conductive hearing losses.