title: Sound pressure level generated by individual portable sound equipment.
abstract: BACKGROUND
  The use of Personal Digital Audio Players can cause hearing injuries, as the sound is generated directly in the ear canal. It is believed that different types of headphones can cause different amplifications, since they cause changes in the volume and resonance of the ear canal according to their depth.
  
  
  OBJECTIVE
  This study aimed to determine the sound pressure to which young individuals are exposed when using Personal Digital Audio Players with two types of headphones: insertion earphones and anatomical insertion earphones.
  
  
  METHODS
  This was an experimental study. The probe microphone measurements were made with different headphones in 54 ears (27 young individuals). The resonance peaks were also recorded.
  
  
  RESULTS
  A statistically significant difference was observed between the evaluated headphones, showing that anatomical insertion earphones had higher levels of sound pressure than insertion earphones for all frequencies measured. There was no correlation between the resonance peak of the closed canal and the frequency where the highest sound pressure level was obtained. There was a significant difference between ears at some frequencies with the different headphones.
  
  
  CONCLUSIONS
  It was concluded that anatomical insertion earphones generate a higher sound pressure level than insertion earphones.
authors.affiliation: Universidade Estadual de Campinas, CampinasSP, Brasil, Aprimoramento em Saúde Auditiva, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brasil.
authors.forename: Izabella dos
authors.initials: Id
authors.lastname: Santos
authors.affiliation: Universidade Estadual de Campinas, Faculdade de Ciências Médicas, Departamento de Desenvolvimento Humano e Reabilitação, CampinasSP, Brasil, Departamento de Desenvolvimento Humano e Reabilitação , Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brasil.
authors.forename: Maria Francisca
authors.initials: MF
authors.lastname: Colella-Santos
authors.affiliation: Universidade Estadual de Campinas, Faculdade de Ciências Médicas, Departamento de Desenvolvimento Humano e Reabilitação, CampinasSP, Brasil, Departamento de Desenvolvimento Humano e Reabilitação , Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brasil.
authors.forename: Christiane Marques do
authors.initials: CM
authors.lastname: Couto
mesh_terms: D000158:Acoustic Impedance Tests; D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D004424:Ear Canal / Q000502:physiology*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D009146:Music; D011312:Pressure; D012737:Sex Factors; D013016:Sound; D055815:Young Adult