[Measurement of real personal noise attenuation using earplugs with the E-A-Rfit system]. / La misura del reale abbattimento soggettivo di rumore con uso di inserti auricolari tramite sistema E-A-Rfit.

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). OBJECTIVES: 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. RESULTS/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.

[And yet there is a risk--do it yourself]. / Eppur c'è rischio--Il bricolage.

Our study has examined the valuation of exposure to dust, noise and hand-arm vibrations (HAVs) during "extra-professional" activities of do-it-yourself, like wood smoothing, considering a group of 8 heterogeneous volunteer subjects (not expert of the sector), to find any kind of variability among the subjects. The results have shown a moderate risk for dust exposure and a realer one for HAVs, also higher noise exposure levels when an aspiration system is added to the sander. It's important that the exposure time considered in this study is not comparable to professional time exposure, cause of the "domestic" feature of this activities. Moreover, data could be influenced by different use conditions, grip and material grounds. It's also significant that there are not controls, formation and information of the subjects about the health risks, as well as ipersusceptibility.