LM327 - The Clinician’s Audibility Toolkit: The Speech Intelligibility Index in Pediatric Audiology

Abstract: This module provides an overview of the speech intelligibility index (SII), highlighting its value in pediatric audiology. We will explain how the SII is calculated and review clinical tools that measure SII. Practical applications are considered across key stages of pediatric hearing healthcare: diagnosis, hearing technology candidacy, hearing aid verification, and management of children who are deaf or hard of hearing. Throughout the session, we will address common clinical questions related to SII. The module concludes with case studies that demonstrate how SII can be integrated into written reports, inform clinical decision-making, and support counseling for families.

Summary: The Speech Intelligibility Index (SII) is a measure for quantifying an individual’s access to acoustic cues in the speech spectrum. Consistent access to these cues is necessary for acquiring spoken language; therefore, the SII has important clinical applications in pediatric audiology. In this learning module, we will provide information about the development and calculation of the SII (both aided and unaided), how the SII can be applied in clinical contexts, and how clinicians can use the SII to quantify auditory access and experience in children with hearing loss.
How the SII is calculated:
The SII quantifies how much audible speech information is available in a signal. Importantly, it takes into account factors such as sensation level, background noise, and distortion. Clinically, the SII serves as a single, interpretable value that reflects auditory access in both unaided and aided listening conditions. The calculation of SII can incorporate individual ear canal acoustics, which influence hearing thresholds and hearing aid output. The calculation also weights certain frequencies more than others based on their importance for speech perception, thus highlighting how the configuration of hearing loss impacts access to acoustic cues essential for speech understanding. These components of the SII calculation make it a personalized and functionally relevant measure of auditory access.
Clinical tools that calculate SII:
There are several tools that can be used clinically to make the SII calculation access to both audiologists and professionals in related fields, such as speech pathologists and teachers of the deaf/hard of hearing. These tools include the count the dot audiogram, online calculators, computer-based audiometers, and hearing aid analyzers.
Clinical applications of SII:
We will discuss several practical applications of the SII in pediatric hearing healthcare during this learning module. These applications range from diagnosis to intervention. We will provide examples of how SII can be incorporated as a counseling tool, how it can be used in the decision-making process for hearing technology candidacy, how it impacts language development in children with hearing loss, and why it is critical that hearing aid verification be completed for children to capture SII information. We will also describe limitations of the SII. Finally, we will provide case studies with specific applications of the SII and concrete examples of how the SII can be incorporated into clinical practice.

Brief Summary of Clinical Takeaways: The clinical takeaway for this session: The speech intelligibility index has multiple applications across pediatric audiology. Audiologists can use the SII as a tool in diagnosis, counseling, hearing technology candidacy, hearing aid verification, and long-term management of childhood hearing loss.

Assumptions: pediatric amplification