title: Acoustic reflex on newborns: the influence of the 226 and 1,000 Hz probes.
abstract: OBJECTIVE
  To analyze the occurrence of acoustic reflex and its threshold on newborns using the 226 and 1,000 Hz probes.
  
  
  METHODS
  Thirty-six newborns with "PASS" results in newborn hearing screening and tympanogram with one or two peaks for both probe tones were included. Group I comprised 20 full-term newborns without risk indicator for hearing loss, and Group II comprised 16 newborns with at least one risk indicator. The study about ipsilateral acoustic reflex thresholds was conducted in 500, 1,000, 2,000, and 4,000 Hz.
  
  
  RESULTS
  The groups presented the acoustic reflex thresholds between 50 and 100 dB for both probe tones. In the comparison between the probes, there were differences in all frequencies evaluated in Group I, with the lowest threshold mean for the 1,000 Hz probe. In Group II, differences were detected at 2,000 Hz. The mean acoustic reflex thresholds were similar in both groups for the 226 Hz probe. There was a difference for the 1,000 Hz probe in all tested frequencies. The percentage of response was higher in both groups for the 1,000 Hz probe. The kappa test showed extremely poor agreement in the comparison of results between both probes.
  
  
  CONCLUSIONS
  The occurrence of acoustic reflex was higher in newborns and its thresholds were lower with the 1,000 Hz probe both for healthy newborns and for newborns at risk.
authors.affiliation: Speech Language Pathology and Audiology Department, Dental School of Bauru, Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Lilian Cássia Bórnia
authors.initials: LC
authors.lastname: Jacob-Corteletti
authors.affiliation: Speech Language Pathology and Audiology Department, Dental School of Bauru, Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Josilene Luciene
authors.initials: JL
authors.lastname: Duarte
authors.affiliation: Speech Language Pathology and Audiology Department, Dental School of Bauru, Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Zucki
authors.affiliation: Speech Language Pathology and Audiology Department, Dental School of Bauru, Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Luciane Domingues Figueiredo
authors.initials: LD
authors.lastname: Mariotto
authors.affiliation: Department of Orthodontics, Pediatric Dentistry and Public Health, Dental School of Bauru, Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: José Roberto Pereira
authors.initials: JR
authors.lastname: Lauris
authors.affiliation: Speech Language Pathology and Audiology Department, Dental School of Bauru, Universidade de São Paulo, Bauru, SP, Brazil.
authors.forename: Kátia de Freitas
authors.initials: Kde F
authors.lastname: Alvarenga
mesh_terms: D000158:Acoustic Impedance Tests / Q000295:instrumentation*; D001309:Auditory Threshold / Q000502:physiology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D012022:Reflex, Acoustic / Q000502:physiology*; D012307:Risk Factors