Spasmodic dysphonia (SD) is a vocal disorder where involuntary movements (spasms) of the muscles inside of the vocal folds (larynx) occur during speech.  This interferes with the production of voice; causing breaks in the voice and also resulting in strained speech.

Also referred to as:

• Laryngeal Dystonia
• Strangled voice

Various Types:
Adductor spasmodic dysphonia (ADSD):  This is the most common form of SD.  Here, the vocal folds spasm in a way that brings them together and stiffens them during speech.  In this state, the vocal folds may be unable to vibrate as needed to produce voice.  The sound of speech is strained and the person with the disorder may have a feeling of being strangled when trying to produce words.

Abductor spasmodic dysphonia (ABSD):  Here, the vocal folds spasm in a way that causes them to open during speech.  In this state, a lot of air is allowed to pass through the throat during speech.  The sound of speech is airy, weak, or has a breathy quality to it.  The person with the disorder may describe themselves as feeling “winded” or being easily exhausted when speaking.

Mixed spasmodic dysphonia:  This is the most rare form of SD.  Here, there the opening and closing muscles of the vocal fold experience spasms.  The sound of speech shows signs of both ABSD and ADSD.

Other information:
In all forms of SD, patients may find themselves able to produce normal (or close to normal) voice when they cry, laugh, or even attempt to sing in a higher pitch.