OBJECTIVE: The  study  aims  to  compare  the  maximum  sound  output  capabilities  of  different earphone types/music style combinations. The study also intends to assess the preferred listening levels (PLL) of test subjects using different earphone types with background noise accession. The study also seeks to determine the presence or absence of a threshold shift on headphone/music style combination PLLs that exceed the recommended noise limit.
METHODS:
Design: Experimental Study
Setting: Tertiary Government Hospital
Subjects: Thirty (30) hearing healthy volunteers were sampled from hospital staff aged 18-40 years with no known history of ear pathology and/or use of any known ototoxic drugs, with normal otoscopy, audiograms of less than 20dB from 125Hz to 8000Hz and no exposure to loud noise from any source within the previous three days.The sound pressure levels (SPL) delivered by three (3) types of earphones (earbud type, in-ear  type,  supra-aural  type)  were  measured  at  maximum  volume  setting  of  a  personal  media player  (iPod,  Apple  Inc.),  while  playing  different  music  genres. The  test subjects  were  asked  to listen at their preferred listening levels (PLL) using the different types of earphones at increasing background noise accession.
RESULTS: The  earbud  type  averaged  the  greatest  SPL  among  the  earphone  types  and  pop music averaged the greatest SPL among the music styles. Comparison of the maximum output capabilities revealed that there was a significant difference among different brands of earphones of the same type. However, no significant difference were found among songs of similar music style and across different music styles in all earphones except the in-ear type. PLL average was at  90.4dB  in  a  silent  environment  with  increasing  intensity  as  background  noise accentuated. Supra-aural earphones registered the least increase in PLL in a loud environment due to its higher background noise-attenuating capabilities.
CONCLUSION: Having a significant difference among earphone types with regard their maximum output  capabilities,  it  is  recommended  to  check  the  specifications  of  the  earphone  type  one intends  to  use.  In  using  personal  media  players  (PMP),  the  volume  should  be  set  at  the  lowest comfortable  level. While  choice  of  music  style  remains  the  discretion  of  the  listener,  the  choice of  music  style  should  be considered  for  long  periods  of  listening.  Because  the  PLL  of  test subjects  were  alarmingly  high,  the  authors  recommend  intervention in  their  listening  habits.  Background  noise  attenuating  capabilities of earphones  play  a  factor  in  reducing  excessive  sound  energy  from reaching  the  ear  reducing  the  PLL  and  decreasing  the  risk  for  noise-induced hearing loss.