Protocol for Rapid, Accurate, Electrophysiologic, Auditory Assessment of Infants and Toddlers.

BACKGROUND: Audiologists often lack confidence in results produced by current protocols for diagnostic electrophysiologic testing of infants. This leads to repeat testing appointments and slow protocols which extend the time needed to complete the testing and consequently delay fitting of amplification. A recent publication (Sininger et al50) has shown how new technologies can be applied to electrophysiologic testing systems to improve confidence in results and allow faster test protocols. Average test times for complete audiogram predictions when using new technologies and protocols were found to be just over 32 minutes using auditory brainstem response (ABR) and just under 20 minutes using auditory steady-state response (ASSR) technology. PURPOSE: The purpose of this manuscript is to provide details of expedited test protocols for infant and toddler diagnostic electrophysiologic testing. SUMMARY: Several new technologies and their role in test speed and confidence are described including CE-Chirp stimuli, automated detection of ABRs using a technique called F MP, Bayesian weighting which is an alternative to standard artifact rejection and Next-Generation ASSR with improved response detection and chirp stimuli. The test protocol has the following features: (1) preliminary testing includes impedance measures and otoacoustic emissions, (2) starting test levels are based on Broad-Band CE-Chirp thresholds in each ear, (3) ABRs or ASSRs are considered present based on automated detection rather than on replication of responses, (4) number of test levels is minimized, (5) ASSR generally evaluates four frequencies in each ear simultaneously with flexibility to change all test levels independently. CONCLUSIONS: Combining new technologies with common-sense strategies has been shown to substantially reduce test times for predicting audiometric thresholds in infants and toddlers (Sininger et al50). Details and rationales for changing test strategies and protocols are given and case examples are used to illustrate.

The status of diagnostic testing following referral from universal newborn hearing screening.

The Joint Committee on Infant Hearing 2000 position statement includes guidelines for the development of Early Hearing Detection and Intervention programs. These guidelines provide specific recommendations for the audiologic test battery for infants who fail a newborn infant hearing screening. The recommended test battery includes electrophysiologic measures such as the ABR, frequency specific electrophysiologic tests, bone-conducted ABR, OAEs, tympanometry using high frequency probe stimuli, and acoustic reflexes. In the Commonwealth of Kentucky, 42 centers are listed as providing follow-up diagnostic testing services for infants failing the newborn hearing screening. The purpose of this investigation was to determine how many of these centers were abiding by the Joint Committee guidelines. Results show that only three of 42 centers listed are providing services that meet the guidelines. Less than 50% of infants identified with hearing loss are referred for genetic evaluations by the audiologist. Only 19 of the 42 sites listed provide amplification services for infants identified with hearing loss.