A variant of spasmodic dysphonia in which the spasms (and their effect on the voice) are sustained rather than intermittent. Tonic variant spasmodic dysphonia is to be distinguished from classic variant spasmodic dysphonia.
Individuals with a tonic variant of adductor spasmodic dysphonia have a sustained strained-sounding voice. Individuals with a tonic variant of abductor spasmodic dysphonia have a voice that is more or less continuously breathy. Tonic variant spasmodic dysphonia goes undiagnosed or misdiagnosed far more frequently than does classic variant spasmodic dysphonia.
Strained and pressed sounding voice (1 of 4)
At speech pitch of B3 (247 Hz), the not only true, but also false cords are continually compressed together and voice is very strained and pressed-sounding.
False cords relax (2 of 4)
Just a note higher, at C4 (262 Hz), false cords relax a little to reveal the true cords.
Voice quality less strained (3 of 4)
An octave above, in falsetto, true cords are now nearly completely seen. Voice quality is less strained. This exemplifies the common but not universal finding that falsetto is less affected by the dystonia than chest register.
Adductory tone during breathing (4 of 4)
This patient's larynx also demonstrates marked adductory tone during breathing, though not to the point of classifying this individual as having a respiratory dystonia component.
Four subtypes of adductor spasmodic dysphonia, tonic variant :
Non dysphonic variant
Stage whisper variant
Vocal fry variant