The Effects of Noise on Speech Intelligibility and Complex Cognitive Performance
The Effects of Noise on Speech Intelligibility and Complex Cognitive Performance

Author: Ryan Laquent Urquhart

Publisher:

Published: 2002

Total Pages: 182

ISBN-13:

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A human factors experiment was conducted to assess whether a reduction in noise at the ear would cause an improvement in speech intelligibility, an improvement in cognitive performance, and/or a reduction in subjective mental workload. Modified Rhyme Test (MRT) stimuli were used to determine intelligibility and specific tests within the Complex Cognitive Assessment Battery (CCAB) were used to assess cognitive performance. The tests chosen from the CCAB were: Tower Puzzle, Logical Relations, and Numbers and Words. These tests were chosen because of the specific set of cognitive functions that they measure which corresponded to command and control tasks. Participants performed the MRT and CCAB tests simultaneously in a 114 dBA noise environment at two speech levels, 83 dB (linear) and 96 dB (linear), using two communication microphones, Gentex Model 1453 and a prototype communication microphone developed by Adaptive Technologies Inc. (ATI). The noise used in the experiment was from a recording made inside a US Army Bradley Fighting Vehicle. Subjective mental workload was assessed using the NASA-TLX and Modified Cooper-Harper (MCH) immediately after the experiment. Results indicated that the communication microphone developed by ATI reduced the noise level at the ear better than the current Gentex microphone. However, the Gentex microphone produced significantly higher speech intelligibility scores at the 96 dB speech level.

Perspectives on the Study of Speech
Perspectives on the Study of Speech

Author: P. D. Eimas

Publisher: Psychology Press

Published: 2013-05-13

Total Pages: 361

ISBN-13: 1134917422

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Published in the year 1982, Perspectives on the Study of Speech is a valuable contribution to the field of Cognitive Psychology.

Speech Understanding in Noise
Speech Understanding in Noise

Author: Katharine Lynn Fitzharris

Publisher:

Published: 2016

Total Pages:

ISBN-13:

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The most common complaint of individuals with hearing loss is their inability to understand speech in noisy environments; thus, speech-in-noise (SIN) has been an area of tremendous research. It has been established that a complex interaction of peripheral and central auditory systems underlies the ability to comprehend speech in degraded environments. Methodologically, however, behavioral and electrophysiological studies have been disparate: where behavioral and clinical testing establishes a variable signal-to-noise ratio (SNR) threshold based on an individual’s performance, studies utilizing auditory event-related potentials (AERPs) tend to use fixed SNR values, resulting in variable performance. Both behavioral and AERP studies have illustrated the impact of stimulus effects on SIN performance, e.g., SNR and masker type. The purpose of this study was to use AERPs in order to evaluate the interactions between peripheral and central systems in the processing of speech. Using behaviorally-established SNR levels (60% correct, 100% correct), two types of background noise (speech-shaped noise, multitalker babble), and two signal types (syllables, words) in an oddball task, AERPs were recorded and analyzed relative to the peak amplitudes and latencies of the N1, P2, and P3. Results from 21 young adults indicate that even when behavioral accuracy is controlled for, there are complex effects of stimulus factors on the neural underpinnings of speech processing.