Normal vocal cord

25 year old healthy male opera singer. There is a lot of action during singing, which is a combination of speech and vocalization. Here he sings a segment of "Old Man River"

25 year old healthy female opera singer. There is a lot of action during singing, which is a combination of speech and vocalization. Here she sings a segment of "O mio caro"

Normal female singer. This arpeggio demonstrates how the pharynx narrows as pitch increases to create a narrower tube for resonance at the higher pitch. There is a touch of vibrato at the end.

This slide downward in pitch demonstrates how the vocal folds shorten in length to decrease pitch. The light is constant so the edges of the vocal folds blur during phonation. The video frame rate on this digital recording was 30 frames per second and the vocal folds are vibrating at over 200 vibrations per second. A rigid scope was used for the recording. (Strobe in larger version)