In several laboratory animal studies, it has been documented that the hearing, vision, and brain can be injured due to exposure to organic solvents. This finding formed the background for a pilot study (n = 16) aimed at identifying new ways of qualifying diagnostics, treatment, and rehabilitation of patients suffering from brain injury due to exposure to organic solvents, also referred to as toxic encephalopathy. Diagnosing toxic encephalopathy is complicated because the symptoms of this type of diffuse brain injury are non-specific. So, it was initially hypothesised that some of the difficulties involved in diagnosing toxic encephalopathy could be minimized by extending the diagnostic procedure. Apart from clinical interviewing and neuropsychological testing, the diagnosis should include the examination of hearing and vision. This will help in achieving new measures that could improve in diagnosing toxic encephalopathy with more certainty. On the basis of ranking, only one patient in the pilot study was considered to have a normal neuropsychological test profile, which was defined as a test profile without any marked deviations when compared with a normal population. A total of 10 patients were considered to have "discrete problems." These patients had a test profile showing either a few strikingly negative results or an array of results slightly below the expected level when compared with a normal population. A total of four patients were considered to suffer from "moderate problems" and one patient from "severe problems." The patients with "moderate problems" and "severe problems" showed consistent negative results and an unambiguous negative test profile. However, the overall results of all neuropsychological examinations performed revealed a dispersed picture. Quite remarkably, all the 13 patients who had their hearing examined showed a loss of hearing, 7 patients complained about tinnitus, and all patients had a history of exposure to both noise and organic solvents, which had not been observed at the initial examination, but seemed to have serious implications for their prognosis and future life.

A population-based study to assess the use of hearing protection devices by older adults during noisy recreational activities was performed. The population-based Epidemiology of Hearing Loss Study was designed to measure the prevalence of hearing loss in adults residing in Beaver Dam, Wisconsin. The use of hearing protection devices during noisy recreational activities was assessed by performing three examinations over a period of 10 years (1993-1995, no. of participants (n) = 3753, aged 48-92 years; 1998-2000, n = 2800, aged 53-97 years; 2003-2005, n = 2395, aged 58-100 years). The recreational activities included hunting, target shooting, woodworking/carpentry, metalworking, driving loud recreational vehicles, and performing yard work using either power tools or a chain saw. The prevalence of using hearing protection devices during any of these activities increased with time (9.5%, 15.0%, and 19.9% at baseline, 5 years, and 10 years, respectively). However, the use of hearing protection devices remained low for most activities. Those under the age of 65 were twice as likely to use hearing protection devices during noisy activities than were older adults. Men, those with a hearing handicap, and those with significant tinnitus were more likely to use hearing protection devices. Smokers and the less educated were less likely to use hearing protection devices. The results demonstrated that many adults expose themselves to potentially damaging recreational noise, leaving them at risk for hearing loss.

Many studies have shown the significant correlation between noise annoyance and noise sensitivity identified by Weinstein's noise sensitivity scale (WNS). However, the validity of the scale has not been sufficiently assessed. This study was designed to investigate the validity of each question in WNS and to develop a more valid noise sensitivity measurement scale. A questionnaire study was conducted in a residential area along trunk roads in Kusatsu, Japan, and 301 responses were collected. In this paper, noise sensitivity was defined as the factor that induced individual variability in reactions caused by noise exposure and that is not affected by the noise exposure. The relationship between noise exposure and answers to each question in WNS was investigated by multiple logistic regression analysis, and the influence of response bias on the score of WNS was examined. The results showed that WNS contained some questions that were inappropriately related to noise exposure level and that the score was affected by response bias. The reported correlation between annoyance and the score of WNS could be confounded by noise exposure and response bias. A noise sensitivity measurement scale named WNS-6B was newly developed, excluding the biased questions from the original WNS and applying binary coding to six-response options in order to reduce the response bias. WNS-6B seemed to be more appropriate to assess noise sensitivity than the original scale.