PP502 - ABR+: A Combined Assessment of Audibility and Suprathreshold Function in a Single Test for Young Children

Abstract:
The auditory brainstem response (ABR) is widely used for threshold assessment, while the frequency following response (FFR) is more effective for evaluating suprathreshold neural encoding, such as in speech-in-noise difficulties and developmental disorders. However, using separate ABR and FFR tests can be challenging in pediatric clinical settings. This study validates the ABR+ stimulus, which combines ABR and FFR into a single test, hypothesizing that ABR+ yields metrics comparable to separate ABR and FFR. Results in 23 children showed ABR+ successfully replicates ABR and FFR, offering a streamlined, effective solution for comprehensive pediatric auditory assessment.

Summary:
Objectives
To validate the ABR+ stimulus as a time-efficient alternative to the complex auditory brainstem response (cABR) for assessing both threshold and suprathreshold auditory function in pediatric patients.

Rationale
The auditory brainstem response (ABR) is commonly used for threshold evaluation, whereas the frequency following response (FFR) is more effective for detecting suprathreshold neural encoding deficits, particularly for challenges like speech-in-noise perception and developmental disorders. Although the cABR offers distinct clinical advantages, time constraints make it challenging to administer separate ABR and cABR tests in pediatric clinical settings. The ABR+ stimulus was developed to combine ABR and FFR in one test, potentially streamlining clinical assessments.

Design
We recorded ABR and FFR responses in 23 children with normal hearing across three conditions: ABR-alone (click at 60 and 80 dB SPL), cABR (using the synthetic syllable /da/), and ABR+ (a combined click and /a/ vowel with a 15-ms silent gap). Analyses included ABR peak latency and amplitude comparisons between ABR-alone and ABR+, and fast Fourier transform (FFT) amplitude comparisons between cABR and ABR+. All recordings followed standard clinical protocols.

Results
No significant differences were observed in ABR peak latencies and amplitudes between the 60 dB ABR-alone and ABR+ conditions. Likewise, FFT amplitudes were comparable between the cABR and ABR+ conditions, suggesting that the ABR+ reliably replicates both ABR and FFR responses in a single, efficient test.

Conclusions
The ABR+ stimulus provides a streamlined approach to assess both threshold and suprathreshold, speech-related, auditory function in pediatric patients, potentially reducing test duration without compromising data accuracy. This method may facilitate broader adoption of suprathreshold assessments in routine pediatric audiology, enabling clinicians to detect neural encoding deficits early, without requiring separate ABR and FFR testing.