Applications of the NTID speech recognition test (NSRT^®)

Abstract

Objective: This study evaluated the diagnostic capabilities of an adaptive speech recognition protocol (NSRT^®) that can be self-administered in non-clinical venues by listeners using internet-based software. Design: All participants were given an audiological evaluation, including pure-tone testing, and responded to the NSRT administered in quiet and + 5 dB SNR listening conditions. The NSRT test materials are sentence-length utterances containing phonetic contrasts, primarily minimal pairs. Study sample: Subjects were 123 adults with normal hearing to moderately severe sensorineural hearing loss (mean age = 55 years, SD = 23). Results: Performance on the NSRT is strongly related to pure-tone thresholds. Linear regression analyses support the utility of the NSRT as a proxy for clinically-obtained hearing thresholds across the octave frequencies 0.5 to 8 kHz, primarily for individuals in the − 10 to 55 dB HL range. Other NSRT results are linked to analyses of phonetic errors and components of aural rehabilitation. Conclusions: Among its numerous results, the NSRT yields quantitative predictions of frequency-specific hearing thresholds, provides insight into the phonetic errors that affect speech understanding in adults who suffer from sensorineural hearing loss, primarily in the − 10 to 55 dB HL range, and has implications for the design of individualized auditory training programs.

Key Words::

• Speech recognition
• hearing thresholds
• phonetic analysis
• auditory training
• adaptive testing
• item response theory
• Rasch measurement

Acknowledgements

The authors wish to thank Dr. Karen Doherty for her work on the companion article, and three anonymous reviewers and Dr. Lisa Mendel for their helpful comments and suggestions regarding revisions to this article.

Declaration of interest: The authors report no conflicts of interest. However, in the interest of transparency, we wish to disclose that NSRT^® (patent pending) is a registered trademark of Rochester Institute of Technology.