title: [A study of effects of head-down bed-rest simulated weightlessness on phonetic features of Chinese].
abstract: OBJECTIVE
  To study the changes of phonetic features of Chinese speech during head-down bed-rest (HDBR) simulated weightlessness.
  
  
  METHODS
  During -6 degrees HDBR in 6 healthy subjects (20-30 years), acoustic-phonetic features were analyzed.
  
  
  RESULTS
  The duration of utterance was slightly increase in the first two days, and recovered after the fourth day of HDBR; mean energy decreased along with time of bed rest, t-tests showed that the decrease in energy of utterances was very significant; a decrease in fundamental frequencies under HDBR was also significant.
  
  
  CONCLUSIONS
  There were certain changes in the acoustic phonetic features under HDBR, some of them were significant.
authors.affiliation: Institute of Space Medico-Engineering, Beijing, China.
authors.forename: Z G
authors.initials: ZG
authors.lastname: Liu
authors.forename: D S
authors.initials: DS
authors.lastname: Huang
authors.forename: S X
authors.initials: SX
authors.lastname: Zheng
mesh_terms: D000328:Adult; D001510:Bed Rest; D002681:China; D018475:Head-Down Tilt; D006801:Humans; D010700:Phonetics; D013060:Speech; D013061:Speech Acoustics; D013997:Time Factors; D018474:Weightlessness Simulation