Glottis

What it means

The glottis is the opening between the two vocal folds in the larynx. In singing and speaking it is set in vibration by the outflowing air stream: the vocal folds open and close in rapid succession, and this vibration produces the fundamental tone of the voice.

Musical use

The vibration frequency of the glottis determines the pitch. Length, tension, and thickness of the vocal folds change finely in the process, so that high or low notes and the various registers of the voice, such as chest and head voice, arise. Too firm or too loose a glottal closure affects the sound, which can then seem pressed or breathy. Vocal teaching attends to a balanced glottal closure, for which the larynx must stay calm and free.

The glottis should be distinguished from the vocal folds themselves, which form the vibrating tissue folds, and from the resonating spaces in throat, mouth, and nose, which shape the sound. A glottal stop denotes a hard onset of vowels and should as a rule be avoided in singing.

Performance practice

Begin vocal exercises with a soft, even onset so that the glottis closes without pressure, and avoid pressing and breathiness. Keep the larynx relaxed and support the tone through breath and posture rather than through force in the throat.