Authors: Francois Deloche¹; Sanna Hou²; Matthew Croteau²; Thomas Fung¹; Georgy Sofronov¹; Viji Easwar²; Sriram Boothalingam¹
¹Macquarie University; ²National Acoustic Laboratories
Background: Newborn Hearing screening programs commonly use auditory brainstem responses (ABR) or otoacoustic emissions (OAEs) to detect hearing loss. A current advantage of ABRs over OAEs is that they can detect neural deficits like auditory neuropathy spectrum disorders (ANSD). We have developed a technique that repurposes the click stimulus and evoked emissions to monitor brainstem reflexes, potentially detecting and aiding in the differential diagnosis of ANSD with just OAEs.
Method: Repeated click trains of 1s were used to evoke OAEs (80 and 90 dB ppSPL, presentation rate: 64 Hz). Responses in the [0–4 ms] and [6–15 ms] windows following each click were analysed to monitor the middle ear muscle (MEMR) and medial olivocochlear (MOCR) reflexes, respectively. Reflex detection was based on a likelihood-ratio score assuming a two-term exponential time course under normal hearing (H1), and a time-invariant model under sensory hearing loss or ANSD (H0).
Results: OAEs were recorded bilaterally in 64 children (24 normal hearing, 20 sensorineural loss, 15 conductive loss, and 5 ANSD). Hearing loss detection was evaluated using ROC analysis and compared with OAE signal-to-noise ratio (SNR). The best performance was obtained by combining MEMR and MOCR detection (AUC: OAE SNR 0.87, MOCR 0.89, MEMR 0.9, MOCR+MEMR 0.93). Ongoing work examines spectral cues to further improve specificity.
Conclusion: OAEs alone can be used to screen for cochlear and neural deficits. Our approach, requiring only conventional OAE recording hardware and fewer operational resources, offers a cost-effective alternative for newborn and post-newborn hearing screening and diagnostics.
