Noise characteristics of surgical space suits

Several studies indicate that the noise generated by performing orthopedic surgery has the potential to cause hearing loss. Noise-induced hearing loss was found in 50% of the orthopedic surgeons studied using audiometric testing, with a greater incidence associated with years of practice. Noise produced by several orthopedic surgical instruments such as saws, drills, and hammers during surgery exceeds 100 dB, especially during knee replacement procedures. In one study, surgical space suits (personal protection systems) were suggested to help protect against noise-induced hearing loss, although space suit manufacturers do not market them as noise-reduction devices. A research protocol was developed to determine if commercially available surgical space suits help to reduce noise at the surgeon's ear. With the commercially available personal protection systems used in this research, there was no significant extra-helmet noise decrease by wearing the space suit. Sound inside the helmet at the level of the ear averaged 61 dBA, approximately the level of conversational speech, which may explain the difficulty the surgical staff may have hearing speech in the operating room when the space suit is worn with the fan on. If surgical noise is to be decreased, earplugs or muffs must be worn not only by the surgeon, but also by all personnel in the operating theater. At greatest risk may be the anesthesiologist, who may experience several orthopedic surgeries in a single day and is positioned close to the patient.