Masking release, processing speed and listening effort in adults with traumatic brain injury

Purpose: This preliminary study explored differences between adults with and without traumatic brain injury (TBI) for speech processing accuracy, processing speed and effort in various conditions of interference.

Methods: Ten adults with TBI and six adults without TBI participated. Speech processing was studied using sentence repetition in six listening conditions with different types of interference, including noise and two simultaneous talkers. Participants repeated sentences and rated effort. Participants also completed standardized tests of cognition, including working memory and processing speed measures.

Results: Sentence repetition accuracy did not differ between groups. However, the TBI group demonstrated slower processing speed than the control group and also reported significantly greater effort in the two-talker condition. Faster processing speed was also correlated with higher accuracy in the two-talker condition.

Conclusions: Results of this study show group similarities in repetition accuracy across listening conditions, but group differences in speed and effort. This preliminary finding, as well as the relationship between processing speed and repetition accuracy, suggests that it is only in the most complex listening conditions that the effects of brain injury may be detectable.