title: [500 Hz masking level difference test for Chinese: a pilot study].
abstract: OBJECTIVE
  A pilot study found the masking level difference (MLD) normal value of Chinese aged from 10 to 40, served to clinical practice.
  
  
  METHODS
  Seventy-three normal persons with hearing threshold < 20 dB and no disorder of otology were divided into three groups: classified 10-20 age as A group, 21-30 age as B group, 31-40 age as C group. MLD of age, gender and race were determined by the audiometer with dual channel by playing audio test disc. Same tests were compared with English language.
  
  
  RESULTS
  The mean value of MLD in Chinese was (11.1 ± 3.4) dB and the 95% normal reference values were between 4.4 to 17.8 dB . There was no difference in term of gender. The value of MLD increased with age. In the term of language, foreign showed high value of MLD than that of Chinese.
  
  
  CONCLUSIONS
  The measuring of MLD depends on age and language but not depends on gender. The normal threshold of MLD depends on age and language should be measured when normal values were applied to assess MLD in clinical practice.
authors.affiliation: School of Speech and Audiology, Zhejiang Chinese Medical University, Hangzhou 310053, China.
authors.forename: Gong
authors.initials: G
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Qi
authors.affiliation: Email: wangyh@vip.sina.com.
authors.forename: Yonghua
authors.initials: Y
authors.lastname: Wang
mesh_terms: D044466:Asian People; D001299:Audiometry; D001309:Auditory Threshold; D002681:China; D006320:Hearing Tests; D006801:Humans; D007802:Language; D010036:Otolaryngology; D010470:Perceptual Masking; D010865:Pilot Projects; D012016:Reference Values