Correspondence between laryngeal vocal fold movement and muscle activity during speech and nonspeech gestures

Abstract

To better understand the role of each of the laryngeal muscles in producing vocal fold movement, activation of these muscles was correlated with laryngeal movement during different tasks such as sniff, cough or throat clear, and speech syllable production. Four muscles (the posterior cricoarytenoid-PCA, lateral cricoarytenoid-LCA, cricothyroid-CT and thyroarytenoid-TA) were recorded with bipolar hooked wire electrodes placed bilaterally in four normal subjects. A nasoendoscope was used to record vocal fold movement while simultaneously recording muscle activity. Muscle activation level was correlated with ipsilateral vocal fold angle for vocal fold opening and closing. Pearson correlation coefficients and their statistical significance were computed for each trial. Significant effects of muscle (p≤0.0005) and task (p=0.034) were found on the r (transformed to Fisher's Z') values. All the PCA recordings related significantly with vocal opening while CT activity was significantly correlated with opening only during sniff. The TA and LCA activities were significantly correlated with vocal fold closing during cough. During speech, the CT and TA activity correlated with both opening and closing. Laryngeal muscle patterning to produce vocal fold movement differed across tasks; reciprocal muscle activity only occurred on cough while speech and sniff often involved simultaneous contraction of muscle antagonists. In conclusion, different combinations of muscle activation are used for biomechanical control of vocal fold opening and closing movements during respiratory, airway protection and speech tasks.

Central nervous system control of the laryngeal muscles in humans

“…These two opposing muscles are used synergistically throughout the pitch range to alter the frequency of vocal fold vibration by changing vocal fold length and tension (Titze et al, 1989). Furthermore, the CT muscle may play different roles in movement depending upon vocal fold position at the time of contraction; it raises vibratory frequency when the vocal folds are in the midline for voicing (Titze et al, 989;, is active for abduction during inspiration and sniff Poletto et al, 2004) and during vocal fold opening for voiceless consonants during speech (Lofqvist et al, 1984).…”

“…A preliminary cross-correlation study examined the relationship between intrinsic muscle activity and vocal fold movement during syllable repetition, cough or throat clear, and sniff (Poletto et al, 2004). By doing a list-wise correlation between a smoothed EMG recording and the change in the opening angle of the vocal folds over time, the relationship between laryngeal muscle activity and movement was determined.…”

“…The LCA and TA muscles are active for vocal fold adduction during cough (Poletto et al, 2004). This adduction occurs immediately following inspiration to close off the upper airway and raise the subglottal pressure.…”

“…This adduction occurs immediately following inspiration to close off the upper airway and raise the subglottal pressure. Next, the PCA muscle is active for vocal fold abduction (Poletto et al, 2004) to provide high levels of air flow for clearing substances from the upper trachea, larynx and hypopharynx. Cough can be triggered by stimulation of the mucosa in the trachea, glottis and supraglottic region.…”

Predictions of Fundamental Frequency Changes During Phonation Based on a Biomechanical Model of the Vocal Fold Lamina Propria

“…Length changes of the vocal fold are known to control fundamental frequencies and are driven by the activities of intrinsic laryngeal muscles, primarily the cricothyroid (CT) and the thyroarytenoid (TA) muscles [19]. Temporal correlation of muscle activation with syllable formation has also been documented [20]. To exemplify the approach, the constitutive model is applied to describe the mechanical response of cadaveric vocal fold tissues obtained from a 66-year-old male subject.…”