title: [Relationship between sample size and variation of means for personal noise exposure in weaving workers].
abstract: OBJECTIVE
  To explore the relationship between sample size and variance of means for personal noise exposure in weaving workers as to contributing evidence for establishing personal noise exposure measurement guideline.
  
  
  METHODS
  A personal noise exposure measurement database from a group of weaving workers was used in the randomized re-sampling data analysis. The sampling cases were one number selecting from one to fifteen at each randomized re-sampling procedure. The randomized re-sampling was one thousand times from original personal noise exposure measurement database to get one thousands of re-sampling database. One thousands of L(Aeq.8 h) mean were calculated by re-sampling databases. The variation of randomized re-sampling means was analyzed for different re-sampling numbers.
  
  
  RESULTS
  The change for narrow trend of maximum, minimum, 95 percent number, 5 percent number of L(Aeq.8 h) mean was faster when randomized re-sampling number was smaller in variation vs randomized re-sampling number curve analysis. After that, the change for narrow trend of L(Aeq.8 h) mean was smooth for increasing the randomized re-sampling numbers. The 95% - 5% of L(Aeq.8 h) mean was about half for randomized re-sampling four cases (3.30 dB) vs one case (7.40 dB), and about one third for seven cases (2.44 dB), and about one fourth for eleven cases (1.85 dB).
  
  
  CONCLUSIONS
  The sample size in personal noise exposure measurement guideline could be selected from four to eleven.
authors.affiliation: Center for Clinical Epidemiological Research, Peking University Third Hospital, Beijing 100083, China.
authors.forename: Yi-ming
authors.initials: YM
authors.lastname: Zhao
authors.forename: Jing-qiao
authors.initials: JQ
authors.lastname: Lü
authors.forename: Lin
authors.initials: L
authors.lastname: Zeng
authors.forename: Shan-song
authors.initials: SS
authors.lastname: Chen
authors.forename: Xiao-ru
authors.initials: XR
authors.lastname: Cheng
authors.forename: Yu-qin
authors.initials: YQ
authors.lastname: Li
mesh_terms: D006801:Humans; D009623:Noise, Occupational / Q000706:statistics & numerical data*; D016273:Occupational Exposure / Q000706:statistics & numerical data*; D018401:Sample Size; D012494:Sampling Studies