Sonninen, "The role of the external laryngeal muscles in length-adjustment of the vocal cords in singing; phoniatric, roentgenologic and experimental studies of the mechanism of pitch change in the voice with special reference to the function of the
sternothyroid," Acta Oto-Laryngologica.
Coppit, et al., "The Functional Impact on Voice of
Sternothyroid Muscle Division During Thyroidectomy," Annals of Surgical Oncology 15, no.
Both sternohyoid & sternothyroid muscles take origin from posterior aspect of manubrium of sternum.
At its origin, it was lying between the origins of sternohyoid & sternothyroid muscles.
It gave a branch to the aberrant muscle in its fleshy part and then joined with 'descendens cervicalis' to complete the ansa cervicalis which continued to supply the sternohyoid & sternothyroid.
In this case, an intermediate layer of muscle has been separated between sternohyoid and sternothyroid. It can be hypothecated that, suprahyoid and infrahyoid muscles form a continuous band of muscles extending from base of the skull to sternum with intermittent attachment to hyoid bone.
Omohyoid differs from the other three infrahyoid muscles (sternohyoid,
sternothyroid, and thyrohyoid) in its course.
EMG surface electrodes were placed on both sides of each singer's larynx over the thyroid cartilage in an effort to isolate the
sternothyroid (ST) and sternohyoid (SH) muscles, the primary depressors and stabilizers of the larynx.
These researchers suggested, "the cricothyroid muscle regulates a steady pitch level, and that the vocalis and lateral cricoarytenoid muscles modulate this pitch level and add changes to the perceived tone quality." (32) During the production of high pitches, the cricothyroid muscle seems to contribute most; the
sternothyroid muscle contributes more to low pitch control.