Hearing thresholds above age- and sex-based norms and an under-recognized hearing screening gap in short-haul truck drivers in Los Angeles, California: a cross-sectional pilot study

Objective To characterize hearing, noise behaviors, and awareness of hearing difficulty in predominantly Hispanic/Latino short-haul truck drivers, and to compare measured thresholds with age- and sex-based norms. Methods In this cross-sectional pilot study we studied 50 short-haul truck drivers in Los Angeles, California, USA, in July 2023. Each completed a health and noise survey and automated audiometry from 250 to 8000 Hz; workplace and in-cab sound levels were measured with a smartphone meter. Thresholds were compared with ISO 7029:2017 age- and sex-based normative values, including their position within the normative distribution. Results Mean age was 51.8 years; 88.6% identified as Hispanic/Latino and 87.0% used no hearing protection. Thresholds exceeded normative medians at every frequency; the sample median fell at or above the 76th percentile across frequencies, most extreme at low frequencies. In an exploratory model, age was associated with the better-ear pure-tone average; years of driving, noise sensitivity, and cardiovascular risk showed no independent association. Among drivers with measured high-frequency loss, 59% reported no perceived decline. Conclusions Short-haul truck drivers had hearing poorer than age- and sex-based norms across frequencies, rarely used protection, and were often unaware of measurable loss. These findings support accessible hearing screening and protection in this underserved workforce.