The Auditory-Cognitive Assessment of Speech Understanding: A Comprehensive Analysis of Construct Validity

Age-related hearing loss, the predominant global cause of hearing loss in middle-aged and older adults, presents a significant health and social problem, particularly affecting speech understanding. Beyond the auditory system, cognitive functions play a crucial role in speech understanding, especially in noisy environments. Although visual cognitive testing is commonly used as an intriguing alternative to mitigate the potential adverse effects of hearing loss on the perception of auditory test items, its efficacy within a hearing-related context is questionable due to construct differences. Therefore, this study aims to investigate the construct validity of auditory and visual versions of cognitive tests in predicting speech understanding, to identify the best suitable auditory or visual cognitive predictor(s) for implementation in the field of audiology.

Fifty-two middle-aged and older adults with normal hearing and 52 with hearing loss were included in the study (mean age for the total group: 67.38 years [SD: 7.71 years], range: 45 to 80 years). Both subgroups were matched based on age, sex, and educational level. Speech understanding in quiet (SPIQ) and in noise (SPIN) was assessed using the ecologically valid Dutch Linguistically Controlled Sentences test. An extensive cognitive test battery was assembled, encompassing measures of sustained attention, working memory, processing speed, and cognitive flexibility and inhibition, through both auditory and visual assessments. Correlation coefficients examined the relationship between the independent variables (demographics and cognition), and SPIQ and SPIN separately. Identified predictors underwent stepwise and hierarchical multiple regression analyses, with significant variables included in final multiple regression models for SPIQ and SPIN separately.

The final multiple regression models demonstrated statistically significant predictions for SPIQ (adjusted R2 = 0.699) and SPIN (adjusted R2 = 0.776). Audiometric hearing status and auditory working memory significantly contributed to predicting SPIQ, while age, educational level, audiometric hearing status, auditory sustained attention, and auditory working memory played significant roles in predicting SPIN.

This study underscores the necessity of exploring construct validity of cognitive tests within audiological research. The findings advocate for the superiority of auditory cognitive tests over visual testing in relation to speech understanding.