Summary of: Mühler, R., Rahne, T., & Verhey, J. L. (2013). Auditory brainstem responses to broad-band chirps: amplitude growth functions in sedated and anaesthetised infants. International journal of pediatric otorhinolaryngology, 77(1), 49–53. https://doi.org/10.1016/j.ijporl.2012.09.028
Auditory brainstem responses (ABR) are useful for evaluating the hearing status of infants that fail newborn hearing screenings or develop a postnatal hearing pathology. The quality of ABR recordings are largely dependent upon individual electroencephalogram (EEG) amplitude and state of arousal, and thus motivates obtaining ABR recordings under natural sleep, sedation or general anaesthesia. One way to reduce the contribution of high EEG levels upon the quality of ABR recordings is to obtain a more robust evoked response, which the CE-Chirp has shown promise. The present study analyzes the amplitude and amplitude growth function of CE-Chirp evoked ABRs retrospectively from 46 infants for comparison against the comparable literature data for adults and to click-evoked ABRs for infants. In addition, the effects of maturation on CE-chirp evoked ABR between 1 and 48 months of age is evaluated. Results show that CE-Chirp evoked ABR amplitudes for two groups of infants separated according to a criterion of 18 month of age are larger relative to responses reported in the literature for click-evoked ABRs from young infants. The CE-Chirp evoked ABRs are not substantially smaller for the older infants than those reported for adults; however, the CE-Chirp evoked ABR amplitudes are smaller for younger infants relative to their older infant and adult counterparts. The results suggest that use of the CE-Chirp evoked ABR improves the chance of overcoming the adverse effects of high EEG noise in ABR recordings and hence, stands to reduce recording time in young infants.
Related course: An Introduction to the CE-Chirp®