[A study on vowel duration and word length of adductor spasmodic dysphonia]

To understand the vowel duration and statement reading of the adductor spasmodic dysphonia (ADSD) patients compared with their normal controls, and provide ideas for clinical diagnosis and treatment.

Twenty-nine ADSD patients were included in the research, with 31 normal controls. All subjects filled in form voice handicap index (VHI) by themselves. Maximum phonetic time (MPT) and maximum loudness phonetic time(MLPT) were tested on /a/ sound for all patients. Also, all the patients were required to read aloud a standard mandarin assay named , duration were measured with Praat5. 0 software after sounds were collected. A one-way t-test was performed to compare spasmodic group with control group on VHI, MPT, MLPT and duration for reading standard sentences. Pearson/Spearman correlation was tested. Result: The VHI of the 29 ADSD patients is 89±12, and their normal controls 15±16, indicating that the VHI in ADSD group is significantly higher than in the control group(P<0. 01). The MPT of the ADSD group is(16. 9±9. 8 s), and the control group is (25. 3±10.0)s, indicating that MPT in the ADSD group is significantly shorter than the control group(P<0. 01). The MLPT of the ADSD group is (15.7±7. 6)s, and the control group is (26. 5±11. 4)s, indicating that MLPT in the ADSD group is significantly shorter than the control group (P<0. 01). The duration of standard sentence reading of the ADSD group is (55.0±14. 2)s, and the control group is (37. 8±4. 8)s, indicating that the duration of standard sentence reading in the ADSD group is significantly longer than the control group (P<0. 01). Correlation analysis showed that MPT and MLPT are related within the ADSD group(r=0. 697,P< 0.01), other indexes being tested have no significant correlations.

The voice disorder condition of the ADSD patients is significantly worse than normal people. Their pronunciations on continuous vowels are not lasting compared with normal people. In the meantime, their ability to read sentences is worse than normal people, needing longer time to complete the reading task. There is a significant correlation between MLPT and MPT, which can be used as an alternative to MPT.