[Phonation onset and simultaneous activation of non-larynx related muscles]

Various voice therapy techniques include not only phonation exercises but also measure to regulate tonus of non-larynx related muscles. This is based on the belief that the use of non-laryngeal muscles may affect laryngeal muscle action during phonation onset und phonation. Here we raised the question if indeed a well defined activation of muscles distant to the larynx may effect phonation onset time and the vibratory cycles following thereafter.

Prospective partly randomized single center pilot study with 8 healthy volunteers. Analysed variables were time of phonation onset and closed quotient (Qx) derived via electroglottgraphy. According to a randomization protocol volunteers had to press a training device (  +  condition) or to keep the hand quiet ( - condition).

Comparism of both conditions did not reveal any significant difference, however Qx tended to be higher in the  +  condition.

The data presented here does not confirm that activation of hand muscles influences phonation onset time. However the preceding vibratory cycles may be altered towards a higher tone of intralaryngeal muscles regulating vocal fold tension. Further studies including more volunteers or patients with functional voice disorders and protocols employing the activation of other muscle groups are warranted in order to shed more light into the interrelationship between larynx and other muscle activation during phonation.