| Disorder | N | Diplophonic voice (n) | Aperiodic voice (n) | Mean age (range) | Sex(M:F) |
|---|---|---|---|---|---|
| Vocal cord paralysis | 40 | 22 | 18 | 60.5(23-93) | 24:16 |
| Vocal cord polyp | 11 | 5 | 6 | 50.5(28-77) | 7:4 |
| Glottic cancer | 9 | 1 | 8 | 56.4(42-76) | 7:2 |
| Leukoplakia | 7 | 0 | 7 | 53.3(48-61) | 4:3 |
| Total | 67 | 28 | 39 | 56.48 | 42:25 |