“Bowing” is a descriptive term to specify that the vocal cords are not matching in a straight line, with only a thin dark line between them at the moment of pre-phonation. Instead, the cords become gently concave or bowed outwards. At the moment of pre-phonation, there is a wider, oval slit between the cords.
Bowing can be physiologic, asymptomatic, and a genetic “given.” In this physiologic type, the bowing will be subtle to mild and there will be good vibratory pattern. When moderate or severe, bowing may more likely be the result of aging, vocal disuse, Parkinson’s disease, or other conditions. Moderate and severe bowing correlate with a degree of vocal cord atrophy and the vibratory pattern can be more flaccid. The voice tends to have a soft-edged quality, a little higher in pitch than normal, and can fade with use. Voice building is the primary treatment, but very occasionally severe bowing is treated with bilateral vocal cord implants.
Vocal Cord Bowing
Bowing of vocal cords and effect of pitch
Four views of vocal cord bowing in the same person
Red herring capillary ectasia and mucosal injuries
Glottic furrow—not just bowing and not glottic sulcus
Voice Building (shorter version):