NIOSH has recently published two studies that estimated the prevalence of hearing difficulty, workplace noise exposure, and non-use of hearing protection device (HPD) among U.S. workers using nationally representative survey data collected from 1997 through 2004. These analyses showed that more than 22 million U.S. workers were exposed to hazardous workplace noise (noise loud enough to require a raised voice to be heard). Over 7 million of these noise-exposed workers (34%) reported that they never used hearing protectors when working in noisy environments. Finally, 12.2 million current U.S. workers (11.4%) have at least some self-reported hearing difficulty. Of these, 3.3 million (24%) are considered to have occupational hearing loss (Tak and Calvert 2008; Tak et al. 2009). Higher prevalence of hearing difficulty was found in several industries, including: mining, manufacturing, construction, agriculture, forestry and fishing, railroads, utilities, trucking service and warehousing, and repair services. Some industry sectors and occupation groups were also found to have significant risk of exposure to hazardous workplace noise.