Conference on Implantable Auditory Prostheses (CIAP)

The Conference on Implantable Auditory Prostheses (CIAP) was held from the 14-19 of July, 2019, at Lake Tahoe, California.

Six researchers from Macquarie University were in attendance including Professor David McAlpine, Dr. Jaime Undurraga, Dr. Lindsey Van Yper, Juan-Pablo Faúndez, Amanda Fullerton, and Ryssa Moffat.

These Macquarie researchers presented papers related to objective measures for bilateral CI fitting and applications of functional near-infrared spectroscopy (fNIRS) in auditory CI research.

Objective measures for binaural CI fitting:

An increasing number of candidates are opting for bilateral implantation. One of the major challenges during bilateral CI fitting is to ensure the integrity and frequency matchedness of channels. Dr. Lindsey Van Yper addressed the importance of frequency matching in a poster on normal hearing adults’ neural responses to matched and mismatched binaural clicks.

Objective measures for CI integrity:

In a podium presentation, Dr. Jaime Undurraga described a novel objective metric for channel integrity, which uses EEG to assess CI users’ temporal processing of amplitude modulated sounds. This novel technique offers a novel approach to understand the underlying mechanisms involved in the coding of sounds whilst it has the potential to be used as a clinical tool to detect poor electrodes in a CI device.

Modelling the electrically stimulated auditory nerve:

One of the key challenges to improve CI technologies is the development of stimulation strategies that take into account the neural mechanisms of the electrically stimulated auditory nerve. To achieve this goal, computational models have become a powerful tool.

In  a poster presentation, Dr. Jaime Undurraga presented some of the results of the computational model developed by the PhD candidate, Matthieu Recugnat. Simulations studied the effect of different auditory nerve health status and the use of novel stimulus shapes to improve CI performance.

Applications of fNIRS in CI-using populations:

fNIRS is a burgeoning method of recording changes in cortical blood flow via near-infrared light. This non-invasive technique is particularly useful for auditory research with CI users, as it is quiet and there are no electrical or magnetic interactions with CI devices. Both Amanda Fullterton and Ryssa Moffat shared results from fNIRS studies. Amanda Fullerton reported on CI users’ cortical responses to auditory stimuli in the auditory and visual cortex. Her approach can offer insight into cross-modal plasticity. During a podium presentation, Ryssa Moffat gave a preliminary description of NH listeners’ cortical and behavioural responses to emotional prosody in natural and degraded speech conditions.

On the whole, CIAP was an excellent opportunity for Professor David McAlpine’s group to learn about current research from other institutions, as well as to receive feedback on their recent work.