Which is the investigation of choice in assessing hearing loss in neonates?
Impedance audiometry is not used in children before 4 months of age because of the characteristics of ear canal. Ear canal is collapsible and a true tympanogram is difficult to get.Similarly behavioral audiometry and free field audiometry are not possible in a neonate. They cannot test the level of hearing. Results of behavioral audiometry will vary due to subjective observation.The only reliable method is brain-stem evoked response audiometry (BERA). In this air conducted clicks are presented through headphones and response picked up from surface electrodes applied to scalp. They are also not affected by sleep and sedation. Latency and morphology of BERA waves changes rapidly with age in infancy and therefore only age specific norms of latency and amplitude are used to interpret results.
Impedance audiometry
Brain-stem evoked response audiometry
Free field audiometry
Behavioral audiometry
Ear