Seminars in Hearing Research at Purdue

Toward Personalized Vagus Nerve Stimulation for Tinnitus: A Physiology Guided Multimodal Approach

Tinnitus affects 10-15% of the population and can substantially disrupt sleep, mental health, and quality of life. Current treatments often provide inconsistent or modest relief because both tinnitus and nervous system responses differ between individuals. Recently, paired auditory and electrical trigeminal nerve stimulation has received FDA approval, yet this therapy remains inconsistent (up to 25% do not show improvement). Noninvasive transcutaneous auricular vagus nerve stimulation (taVNS) has shown similar, less-than-optimal results as trigeminal stimulation, but has the added benefit of sympathetic stress reduction. A key barrier to progress with the taVNS technique is an inability to induce consistent and predictable physiologic changes with stimulation, as there is an absence of personalized frameworks that can tune stimulation parameters to an individual’s unique physiological state, perceptions, and comfort. We developed a research platform to personalize taVNS by combining ear based stimulation with real-time measures of brain and body responses. The system synchronizes brain activity and oxygenation, pupil size, heart rate variability, skin conductance, gastric activity, blood pressure and brief surveys of comfort and perception. Additionally, calibrated earphones standardize sound presentation, while a personalization algorithm identifies settings that balance physiological response and participant comfort. Our ongoing studies are comparing forms of stimulation: electrical based (traditional), and thermal and vibration based (novel). The goal of this work is to move away from a "one-size-fits-all" approach and toward personalized medicine. This work is a vital step toward creating a new generation of wearable devices that can provide predictable, life-changing relief for the tinnitus community.

The Effects of Earplugging on Blast-Induced Hearing Loss

Blast-induced hearing loss contributes to the high levels of hearing difficulties reported among military personnel. While ear plugs are provided to military personnel for protection, hearing damage still occurs. Blast exposure is a common source of auditory trauma during military operations and can damage both peripheral and central auditory systems in a single exposure, even without tympanic rupture. Previous work in our lab has characterized blast induced damage to peripheral and central auditory pathways at the 14 and 28-day timepoints post-blast, showing loss of OHC integrity as measured by DPOAE, reduction of click ABR amplitudes, and temporal modulation processing impairments. In this project, we look at electrophysiological measures of blast-induced hearing loss shortly after exposure and over a 28-day recovery period and we show the effects of earplugging on protecting the central auditory pathway. Preliminary results show earplugging protects ABR thresholds and measures of cochlear function but fails to protect central auditory systems as measured by envelope following responses (EFRs). Our working hypothesis is that earplugging protects peripheral systems from damage but fails to protect more complex temporal encoding because earplugs protect the cochlea but do protect from blast-induced traumatic brain injury. This work is a crucial step in better understanding blast-induced hearing loss and the role conventional hearing protection plays in protecting from it.

Not Just Noise:  Hormonal Variability in Auditory Processing

Sex differences are becoming an increasingly important variable in hearing research and are often treated as a simple comparison between males and females or as another source of variability in the data. Sex differences are not binary or static, and biological factors, such as endogenous hormones, that vary within an individual may influence auditory function. Estrogen is suggested to mediate sex-related differences in auditory processing. However, we do not yet understand how estrogen may mediate sex-related differences in temporal processing. We hypothesized that temporal processing would vary across low-estrogen (LE) and high-estrogen (HE) phases of the female menstrual cycle, with greater differences compared to males emerging during the HE phase. Premenopausal healthy females and age-matched males participated in behavioral temporal processing measures using gap-detection thresholds. Female participants were tested across LE and HE phases, with males included as a comparison group. Overall, temporal processing varied by biological group and stimulus type, with poorer performance observed during the HE phase and greater difficulty for speech-shaped noise than broadband noise. These preliminary findings suggest that hormones may provide important information about why auditory performance differs between and within individuals over time. This may also be clinically relevant as temporal processing is particularly important in complex listening environments and is not always captured by standard measures of hearing sensitivity. Therefore, considering hormonal variability may provide a more sensitive approach for understanding individual differences in hearing and, ultimately, how we interpret both behavioral and clinical auditory measures.

The Marine Biological Laboratory Summer School Experience: Exploring Hearing and Balance from Cells to Systems

In summer 2026, I participated in the intensive three-week Biology of Hearing and Balance course at the Marine Biological Laboratory in Woods Hole. The course combined lectures with extensive hands-on laboratory training spanning auditory and vestibular science, from inner-ear development and hair-cell function to central neural coding, hearing loss, and cochlear prostheses. Experiments included chick utricle and neonatal mouse cochlea dissections, tissue culture and immunostaining, inner-ear paint fills, confocal imaging and image analysis, scanning and transmission electron microscopy, and electrophysiological recordings from hair cells and brain slices. We also explored zebrafish lateral-line function, vestibular reflexes, ABR and DPOAE measurements, and in-vivo recordings from the auditory nerve, inferior colliculus, and auditory cortex. I completed two mini-projects examining zebrafish lateral-line afferent responses and modulation coding across the gerbil auditory pathway. In this talk, I will share highlights from these experiments, including some of the fascinating images and recordings we collected, and reflect on this immersive scientific experience.

From the Cochlea to the Brain: Investigating Parkinson’s Disease Pathology in the Auditory System

Auditory abnormalities are increasingly being recognized as non-motor features of Parkinson's disease (PD), but the processes underlying these alterations are not yet understood. My dissertation research aims to address this gap by combining two fields of study: α-synuclein pathology in PD and auditory neuroscience. Through my work in Dr. Allison Schaser's lab, I have used α-synuclein preformed fibril (PFF) models to investigate how pathology originates and propagates through connected brain areas, while my work in Dr. Jane Mondul's lab has focused on olivocochlear circuits and their response to sound. Bringing these two research areas together led me to ask how α-synuclein pathology might affect the auditory system. This question is particularly relevant because α-synuclein is normally expressed within the cochlea, especially at efferent neuronal terminals, yet whether pathological α-synuclein can be induced locally and subsequently propagate through connected auditory circuits remains unknown. My dissertation will investigate whether cochlear delivery of α-synuclein PFFs can trigger local α-synuclein pathology that spreads to connected central auditory areas. I will establish a feasible strategy for cochlear PFF delivery, characterize the temporal progression of pathology in peripheral and central auditory pathways, and assess associated changes in auditory function. I hypothesize that cochlear PFF exposure will induce local α-synuclein pathology that later appears in connected auditory areas and is associated with alterations in auditory function. This model will provide a novel approach to investigating α-synuclein pathology in the auditory system and help clarify its potential contribution to hearing impairment in PD.

Investigating the Brain-Body Connection:  Realistic Speech Perception Outcomes in CI Users.

Cochlear implant (CI) users vary dramatically in speech perception performance post-implant, yet current clinical assessments fail to explain or predict this variance in real-world environments. Potential factors contributing to CI user outcomes have previously been measured without considering interactions between multiple systems such as the brain-body connection. Additionally, CI users are not assessed for speech perception in a clinic beyond word recognition or sentence repetition tasks. These clinical assessment tasks overlook the role that listening effort, where neural resources are reallocated to support increased auditory processing demands, plays in individual CI user speech perception. Consequently, clinical assessments fail to capture the wide range of CI user performance. This individual variability may be revealed in brain-body correlates of the listening effort processes required to support speech comprehension. The objective of this research is to map the neurophysiological signatures of naturalistic speech perception and listening effort in CI users. The central hypothesis is that low-performing CI users will exhibit brain-body signatures characterized by inefficient neural resource allocation, heightened autonomic arousal responses, and a reduction in listening effort-influenced attentional processes during adverse listening conditions. In this talk, I will present my current F31 specific aims to analyze individual brain-body signatures of listening effort in both normal-hearing and CI users.

Acoustic trauma causes changes in IL-33 cellular location.

IL-33 is a cytokine in the IL-1 family that is stored in the nucleus then released into the cytoplasm and extracellular space upon tissue damage. Free IL-33 binds to its receptor (ST2) forming the IL-33-ST2 alarmin pathway. Previous work has shown that IL-33 is present in cells of the inner sulcus of the cochlea, however little is known about its existence in other cell types and its role in response to tissue damage. Through cochlear histology, we observed the release of IL-33 into the extracellular space upon tissue damage at one day post noise exposure and little change in the number of IL-33 positive nuclei compared to non-noise exposed controls. In other systems, extranuclear IL-33 expression is not generally expected beyond one day. In the cochlea, at one week post noise exposure, a reduction in IL-33 positive nuclei and persistent, diffuse cytoplasmic expression was observed. Our findings suggest that at baseline IL-33 is confined to the nucleus, and at one day post noise exposure cellular location changes. Pillar cells show cytoplasmic IL-33, indicating that more cells participate in IL-33 signaling. IL-33 stays elevated for longer than one day, which may indicate an ongoing trigger for IL-33 signaling after acoustic trauma and could prevent the resolution of inflammation as in other tissues. Additionally, auditory brainstem response and acoustic startle response testing was conducted one day and one week after exposure to correlate auditory thresholds with IL-33 immunofluorescence. Understanding the timeline of IL-33 expression after acoustic trauma may help to identify targets for the development of anti-inflammatory interventions with the goal of preventing or mitigating noise-induced hearing pathologies.

Looking Back, Moving Forward: 20 Years of the Doctorate of Audiology

Following several years of discussion and development, the Doctorate of Audiology (Au.D.) degree was officially adopted in 2007 as the entry-level degree for clinical practice. As we approach 20 years of the Au.D. degree, it is timely to reflect on the initial goals and progress achieved. In this session, we will begin by reviewing the factors that motivated a transition to the doctoral degree. Then we will assess progress toward these goals, evaluated by peer-reviewed education research, editorial reviews, and recently conducted interviews with leaders who helped establish the Au.D. We will conclude with a discussion of how we can continue to advance the professional degree to best serve the needs of audiologists and their patients. This is a practice presentation for a talk that will be given at the 2026 ASHA Convention in Indianapolis in November. 

Looking Back, Moving Forward: 20 Years of the Doctorate of Audiology

Research impact begins well before an article is published. Decisions about data management, publishing pathways, and scholarly identity influence how research is preserved, discovered, shared, and connected to the people who conduct it. In this session, specialists from Purdue Libraries will present practical strategies and campus resources that support researchers across the full research lifecycle. Topics will include: Managing and sharing research data: Effective data management planning, Purdue’s data-support ecosystem, and how and when to use the Purdue University Research Repository for sharing and preserving research outputs. Navigating open access: Open access publishing pathways, Purdue Libraries publishing support, and zero-cost options that can make research more broadly available. Managing research identity: Researcher profiles, persistent identifiers such as ORCID, and strategies for connecting researchers consistently with their publications, data, and other scholarly contributions. Communicating research impact: Ways these practices work together to improve the visibility, discoverability, and accurate representation of research. Designed for researchers across disciplines and career stages, the session connects these practices to a larger goal: publishing and communicating research with purpose.