Cognitive-linguistic demands and speech breathing.

This investigation examined the influence of cognitive-linguistic processing demands on speech breathing. Twenty women were studied during performance of two speaking tasks that were designed to differ in cognitive-linguistic planning requirements. Speech breathing was monitored with respiratory magnetometers from which recordings were made of the anteroposterior diameter changes of the rib cage and abdomen. Results indicated that speech breathing was similar across speaking conditions with respect to nearly all measures of lung volume, rib cage volume, and abdomen volume. Task-related differences were found for certain fluency-related measures. Specifically, the number of syllables produced per breath group was smaller, average speaking rate was slower, and average lung volume expended per syllable was greater under a higher cognitive-linguistic demand condition than under a lower-demand condition. These differences were explained by the fact that silent pauses, particularly those associated with expiration, were more prevalent and longer in duration under the higher-demand condition. It appears that the mechanical behavior of the breathing apparatus during speaking generally is unaffected by variations in cognitive-linguistic demands of the type investigated; however, fluency-related breathing behavior appears to be highly sensitive to such demands.