Spasmodic dysphonia is a voice disorder that is characterized by a strained, strangled voice quality with voice breaks intermittently throughout speech. It may not affect singing or single vowel production. It is a dystonia (cramp) of the laryngeal muscles that are involved in voice production.
The speech of a person with spasmodic dysphonia has non rhythmic breaks that arrest the sounds mid-word or a different type causes breathy breaks where air escapes after vowels. It is worse on the telephone. It can be very stressful and interferes with social interaction as well as business interactions. Speech therapy can help reduce the tension that arises during this effortful speech production. Botox (Botulinum Toxin) injections into the laryngeal muscles can help to smooth out the voice for 3-4 months at a time and eliminate the breaks and reduce the effort of speaking. Tremor is slightly different and is a more rhythmic shaking of the voice. It is present during single vowel production and can make someone sound sad or scared. It also can be worse with stress or embarrassment. Some medications taken by mouth may be helpful to treat tremor. Vocal tremor can be a part of essential tremor which is a hereditary condition and the person can develop tremor in head or hands. If tremor is severe, botox injections to the larynx may be a useful adjunct. Both spasmodic dysphonia and tremor can affect voice and can be managed to improve voice and functioning.