Function of strap muscles in speech

Abstract

Association of cricothyroid activity with high or rising fundamental frequency (f0) and strap activity with low or falling f0 in speech has been confirmed by numerous electromyographic experiments. The purpose of this study is to ascertain whether the role of the strap muscles in lowering f0 is analogous to that of the cricothyroid in raising f0. An electromyographic investigation of the sternohyoid and cricothyroid muscles was performed with speakers of English and Thai. It was found that there were indeed peaks of strap activity during low f0 and peaks of cricothyroid activity during high f0. However, examination of the timing of muscle activity with respect to f0 revealed that the cricothyroid differs from the strap muscles in that the cricothyroid begins to increase in activity prior to the onset of the f0 rise, whereas the increase of strap muscle activity begins after the onset of the f0 fall.