Cognitive spare capacity and speech communication: a narrative overview.

Mary Rudner,Thomas Lunner

doi:10.1155/2014/869726

Abstract

Background noise can make speech communication tiring and cognitively taxing, especially for individuals with hearing impairment. It is now well established that better working memory capacity is associated with better ability to understand speech under adverse conditions as well as better ability to benefit from the advanced signal processing in modern hearing aids. Recent work has shown that although such processing cannot overcome hearing handicap, it can increase cognitive spare capacity, that is, the ability to engage in higher level processing of speech. This paper surveys recent work on cognitive spare capacity and suggests new avenues of investigation.

Highlights

Speech is the main mode of communication for most people
We suggest that cognitive training that targets the multitasking abilities inherent in speech understanding under adverse conditions may improve Working memory (WM) capacity and result in better speech understanding in adverse conditions
WM capacity and executive function are engaged in unravelling the speech signal

Summary

Introduction

Speech is the main mode of communication for most people. If speech understanding is compromised by noise or hearing impairment, communication may become harder, leading to limitations in social participation. Speech comprehension requires the auditory ability to hear the signal and the cognitive ability to relate this information to the existing knowledge stored in semantic long-term memory [1, 2]. Even moderate degrees of hearing impairment lead to decrease in neural activity during speech processing and may contribute to grey matter loss in primary auditory cortex [17, 18]. An informational masker includes cues in terms of pitch or temporal fine structure that may help segregation and dips in the masker may reveal portions of the target signal This may result in the listener perceiving fragments of a target signal that need to be pieced together to achieve understanding. An informational masker may include semantic information that distracts the listener from the target signal and needs to be inhibited

Working Memory and Speech Comprehension

Cognitive Spare Capacity for Communication

Findings

Conclusion