Audiometry with pupil response
Human hearing is generally evaluated through the individual feedback of patients. In standard hearing tests, the feedback from apatient consists in pressing a button, raising a hand, or giving a verbal response to confirm or deny the detection of tones at varyingamplitudes and frequencies. This approach relies on the direct involvement of the patient, and it cannot be suitable for patientsunable to follow instructions or pretender patients. This standard hearing, based on a subjective examination and patientcollaboration, is particularly critical in a wide range of patients: pre-lingual infants, new-born, adults who wrongly indicate theirhearing capabilities.In this context, the measurement of cognitive resource allocation during hearing perception, or delivering listening efforts, providesvaluable insight into the factors influencing auditory processing. In recent years, many studies not limited to the field of hearingscience have measured the pupil response evoked by auditory stimuli. In APURE, we propose the use of the pupillary dilationresponse (PDR), a short-latency component of the orienting response evoked by novel stimuli, as an indicator of sound detection.PDR can be considered a physiological signal and requires no voluntary reports. The main purpose of this project is to transform theaudiometric test from a subjective to an objective examination.APURE project will consider pupil size as an objective measurement in deaf children or in adult not-collaborating patients unable toreport their hearing perception. For these purposes, we will develop a wearable pupillometric device to perform easy measurementsof pupil size. With respect to other neurophysiological measurements, pupil size recordings will be performed with a miniaturizedeasy-to-use device that does not require any specific patient preparation, being utilizable in the patient‘s environment.The objective correlation between audio signals and pupil size will be analysed by applying the stimulus-triggered averagetechnique. Pupils of non-collaborative patients will be monitored with an infrared video camera during a standard hearing test inwhich normal subjects should indicate by button press whether they heard noises. During the final stage of the project, the systemperformance in automatic detection of pupil response after a stimulus will be compared and evaluated with the results of a standardaudiometric test performed on normal subjects to verify its accuracy, reliability, and compliance for clinical use.In the near future, our findings could lead to the development of innovative glasses with oculometry, able to change the colour of theframe based on the PDR (i.e., a colour change associated with hearing perception). and could be used not only for providingfeedback on hearing perception but also to evaluate emotional states and stress. The oculometry simply recorded by theoculometry-glasses could become a new parameter of health.