Components of Auditory Closure

Auditory closure (AC) is an aspect of auditory processing that is crucial for understanding speech in background noise. It is a set of abilities that allows listeners to understand speech in the absence of important information, both spectral and temporal. AC is evaluated using monaural low-redundancy speech tasks: low-pass filtered words (LPFW), time-compressed words (TCW), and words-in-noise (WiN). Although not previously used, phonemic restoration with words (PhRW) is also a speech task that has been proposed as a measure of AC. In the present study, four tasks of AC, that are listed above, were used to evaluate AC skills in 50 adult females with normal hearing. Using pair-wise correlations, there were no significant relationships among LPFW, TCW, and WiN. As a result, these three tasks were considered to be independent components of AC that represented the AC abilities of spectral reconstruction, temporal resolution, and auditory induction, respectively. Multiple linear regression analysis with LFPW, TCW, and WiN as variables revealed that PhRW is accomplished using temporal resolution. The findings of this study show that no single task of AC is representative of the entire process and that further research is warranted to more completely define the skills that make AC possible.