Evaluation of the CochSyn Device in Clinical Practice

Cochlear synaptopathy (CS) is a new type of sensorineural hearing loss (SNHL) and is related to ageing, noise exposure and ototoxicity. There is currently no diagnostic test of CS on the market, whereas CS is an important form of SNHL. CS occurs before the golden standard clinical hearing test (pure- tone audiogram in which participants raise their hand when hearing tones of different frequencies and the threshold of hearing is determined), shows any signs of hearing damage. The sponsor has developed a new test, the CochSyn test that may quantify SNHL earlier than the audiogram. The newly developed test is based on auditory evoked potentials. This is a method in which an auditory stimulus is presented, and encephalogram (EEG) electrodes capture the sound-evoked brain potentials. The most popular auditory evoked potential metric to diagnose sensorineural hearing loss (SNHL) is the auditory brainstem response (ABR). Even though it can be assumed that the ABR wave-I amplitude will be sensitive to CS in humans, it may not be a differential marker for it, and hence other candidate auditory evoked potential markers for CS have been investigated. In particular, the envelope-following-response (EFR), has also been shown to be specific to CS. The sponsor has performed several research studies on the CochSyn test that used commercially available research equipment in either humans or research animals . These data show that our marker is sensitive to ototoxic-induced CS in research animals and demonstrates an age-related decline in humans, and a superiority in terms of test-retest reliability and sensitivity compared to clinical ABR wave-I, or other evoked potential, markers. These promising data, the lack of a method to identify CS and the lack of commercially available hardware to conduct the CochSyn test in a clinical setting motivate the need for the development of the CochSyn test and device. In this study, the sponsor wish to test the performance of its new method (the CochSyn test) in listeners with or without self-reported hearing difficulties using a newly developed hardware prototype (the CochSyn device), dedicated for the CochSyn test in clinical practice.