Psychometric Comparison of the Hearing in Noise Test and the American English Matrix Test

The hearing in noise test (HINT) is the most popular adaptive test used to evaluate speech in noise performance, especially in context of hearing aid features. However, the number of conditions that can be tested on the HINT is limited by a small speech corpus. The American English Matrix test (AEMT) is a new alternative adaptive speech in noise test with a larger speech corpus. The study examined the relationships between the performance of hearing aid wearers on the HINT and the AEMT.

To examine whether there was a difference in performance of hearing aid wearers on the HINT and the AEMT. A secondary purpose, given the AEMT's steep performance-intensity function, was to determine whether the AEMT is more sensitive to changes in speech recognition resulting from directional (DIR) microphone processing in hearing aids.

A repeated measures design was used in this study. Multiple measurements were made on each subject. Each measurement involved a different experimental condition.

Ten adults with hearing loss participated in this study.

All participants completed the AEMT and HINT, using adaptive and fixed test formats while wearing hearing aids. Speech recognition was assessed in two hearing aid microphone settings-omnidirectional and fixed DIR. All testing was conducted via sound field presentation. Performance on HINT and AEMT were systematically compared across all test conditions using a linear model with repeated measures.

The results of this study revealed that adult hearing aid users perform differently on the HINT and AEMT, with adaptive AEMT testing yielding significantly better (more negative) thresholds than the HINT. Slopes of performance intensity functions obtained by testing at multiple fixed signal-to-noise ratios, revealed a somewhat steeper slope for the HINT compared with the AEMT. Despite this steeper slope, the benefit provided by DIR microphones was not significantly different between the two speech tests.

The observation of similar DIR benefits of the HINT and AEMT suggests that the HINT and AEMT are equally sensitive to changes in speech recognition thresholds following intervention. Therefore, the decision to use the AEMT or the HINT will depend on the purpose of the study and/or the technology being investigated. Other test related factors such as available sentence corpus, learning effects and test time will also influence test selection.