Well, during menstruation hormonal shifts cause the cords to become edematous (swollen). This inflammation occurs just prior to the actual onset of your cycle due to increased blood supply to the larynx, causing menstrual dysphonia, an impairment of the voice. It is evidenced by hoarseness, laryngitis, vocal fatigue, less vocal control or just problems hitting high notes.
Yo, so I gotta audition but I just started bleeding and I got period voice, so this will be a shit show.
Teacher: You seem to be a little hoarse and fatigued, is it that time of the month?
Student: Yess.. My period voice is in full swing.
*practices and sounds like crap* DAMN YOU PERIOD VOICE.