title: [Measurement of real personal noise attenuation using earplugs with the E-A-Rfit system].
abstract: BACKGROUND
  The assessment of efficiency of hearing protection devices (HPDs), conducted above statutory limits, must be made using a standardized method while devices are worn; however, standardized and suitable laboratory conditions are difficult to encounter at the workplace. To overcome this problem, there are methods of measurement at the workplace such as "field-microphone-in-real-ear" (F-MIRE).
  
  
  OBJECTIVE
  The study was concerned with the measurement of real noise attenuation using earplugs and a new evaluation system: we checked the difference between "real" attenuation (at workplace) and "theorical" attenuation (reproduced in the laboratory) as stated by the manufacturer.
  
  
  METHODS
  We used the E-A-Rfit computerized method, which measures the loss of attenuation of earplugs in the ear, calculating the difference of sound pressure between an "outside" microphone and an "inside" one, in relation to the same earplug. The measurements at the workplace were carried out on eight subjects with good hearing levels (aged between 20 and 25 years), who were trained to wear the devices correctly. After the tests carried out with the E-A-Rfit system, which does not require a subjective answer, we obtained graphs and tables showing real noise attenuation.
  
  
  CONCLUSIONS
  We propose a comparison between hearing threshold for frequency, personal attenuation rating (PAR) and single number rating (SNR, provided by manufacturer): a difference of 10 dB (PAR 27 db vs. SNR 37 dB) was clearly evident although dissimilar methods were used to obtain such values. The instrument is rapid, simple and objective to use and also allows personalized information and training for every worker.
authors.affiliation: DIM (Dipartimento Interdisciplinare di Medicina) - Cattedra di Igiene Industriale UNIBA, Bari. filippo.cassano@uniba.it
authors.forename: F
authors.initials: F
authors.lastname: Cassano
authors.forename: Ingrid
authors.initials: I
authors.lastname: Aloise
authors.forename: G
authors.initials: G
authors.lastname: Labianca
authors.forename: V
authors.initials: V
authors.lastname: Gaccione
authors.forename: C
authors.initials: C
authors.lastname: Mazzotta
authors.forename: F
authors.initials: F
authors.lastname: Cardascia
authors.forename: Michela
authors.initials: M
authors.lastname: Garavaglia
authors.forename: R S
authors.initials: RS
authors.lastname: Scarselletta
authors.forename: L
authors.initials: L
authors.lastname: Di Lorenzo
mesh_terms: D000328:Adult; D004430:Ear Protective Devices; D004867:Equipment Design; D006801:Humans; D009623:Noise, Occupational / Q000517:prevention & control*; D055815:Young Adult