title: The influence of speech stimuli contrast in cortical auditory evoked potentials.
abstract: Studies about cortical auditory evoked potentials using the speech stimuli in normal hearing individuals are important for understanding how the complexity of the stimulus influences the characteristics of the cortical potential generated.
  
  
  OBJECTIVE
  To characterize the cortical auditory evoked potential and the P3 auditory cognitive potential with the vocalic and consonantal contrast stimuli in normally hearing individuals.
  
  
  METHODS
  31 individuals with no risk for hearing, neurologic and language alterations, in the age range between 7 and 30 years, participated in this study. The cortical auditory evoked potentials and the P3 auditory cognitive one were recorded in the Fz and Cz active channels using consonantal (/ba/-/da/) and vocalic (/i/-/a/) speech contrasts.
  
  
  METHODS
  A crosssectional prospective cohort study.
  
  
  RESULTS
  We found a statistically significant difference between the speech contrast used and the latencies of the N2 (p = 0.00) and P3 (p = 0.00) components, as well as between the active channel considered (Fz/Cz) and the P3 latency and amplitude values. These correlations did not occur for the exogenous components N1 and P2.
  
  
  CONCLUSIONS
  The speech stimulus contrast, vocalic or consonantal, must be taken into account in the analysis of the cortical auditory evoked potential, N2 component, and auditory cognitive P3 potential.
authors.affiliation: Department of Speech and Hearing Therapy, School of Dentistry, University of São Paulo, Bauru campus, Brazil. katialv@fob.usp.br
authors.forename: Kátia de Freitas
authors.initials: Kde F
authors.lastname: Alvarenga
authors.forename: Leticia Cristina
authors.initials: LC
authors.lastname: Vicente
authors.forename: Raquel Caroline Ferreira
authors.initials: RC
authors.lastname: Lopes
authors.forename: Rubem Abrão da
authors.initials: RA
authors.lastname: Silva
authors.forename: Marcos Roberto
authors.initials: MR
authors.lastname: Banhara
authors.forename: Andréa Cintra
authors.initials: AC
authors.lastname: Lopes
authors.forename: Lilian Cássia Bornia
authors.initials: LC
authors.lastname: Jacob-Corteletti
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000293:Adolescent; D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D001309:Auditory Threshold / Q000502:physiology*; D002648:Child; D015331:Cohort Studies; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011930:Reaction Time; D055815:Young Adult