Hearing Conservation

Hearing Conservation

Hearing conservation programs in industrial settings provide protection for employees exposed to noise at work. Employee noise exposure for most industries has been regulated by the Occupational Safety and Health Administration (OSHA) since 1971 by specifying an equivalent exposure limit of 90 dBA time-weighted-average (TWA) sound level for an 8-hour work shift. OSHA regulations (since 1983) require enrolling employees in a comprehensive Hearing Conservation Program (HCP) that includes noise measurement, engineering control, audiometric testing, education and training, use of hearing protection, record keeping, and program evaluation. OSHA has recognized the primacy of engineering control as the first line of defense for reducing noise exposure, but over the years has allowed use of hearing protection to meet exposure criteria. More recently, many of our clients have renewed their interest in using engineering control methods to meet exposure guidelines and loss control targets. From inception in 1988, Associates in Acoustics, Inc. has pursued engineering control methods as our primary method for supporting our client needs for reducing noise exposure at their facilities. We specialize in providing noise control solutions for industrial sites across multiple business sectors including manufacturing, petrochemical, pharmaceutical, and mining. Click on our Noise Control tab for details about services provided for noise reduction of sources throughout your facility.

In addition to engineering control, we provide noise exposure assessments for workers potentially exposed to noise in excess of the regulatory limit. Noise exposure evaluations use personal dosimeters worn by selected employees to determine their daily exposure for the entire work shift. Portable monitoring devices worn on the employee’s shoulder sample several times per second to produce an accumulated noise exposure for the work shift that can be displayed as a percent of the maximum dose or as an equivalent average sound level for the test period. Comparing the exposure results for each sampled employee to the OSHA regulatory criteria or to best-practices exposure criteria can help clients quantify the risk of noise exposure for each group of employees that have been tested. For those employees exposed to 50% or more of the OSHA exposure limit, enrollment in a HCP is mandatory and hearing protection devices must be made available to employees working above this limit. Dosimetry testing can simultaneously calculate three separate measurement criteria during one sampling period for those industries using more than one exposure criteria to manage their HCP. Knowing the exposures for representative job classifications at an industrial site provides necessary information to determine regulatory compliance, evaluate potential risks, and manage the HCP.

During personal dosimetry testing periods, we also take sound level measurements in each production area to create a noise contour map of the facility. Contour maps provide a clear visual view of sound levels contributing to noise exposure for employees working in each department. Maps can be displayed as a series of lines of equal noise level superimposed on an electronic map of each work area or as a series of color-coded shaded areas showing noise levels in 2-3 dB increments. Contour maps provide a guide to areas that need engineering control focus and allow clients to post areas above 85 dBA (or their chosen sound level criteria) with signage requiring the use of hearing protection if their facility has this requirement.

Associates in Acoustics, Inc. also has partners to assist clients with audiometric testing, analysis, certification training for test personnel, and audiogram program review to meet OSHA requirements for employees enrolled in a HCP.