• The employer’s monitoring program must be designed to identify all employees who should be included in a company’s hearing conservation program.

Employers must develop and implement a monitoring program whenever information indicates that any employee’s exposure may equal or exceed the action level. The sampling strategy must be designed to identify all employees for inclusion in the hearing conservation program and enable the proper selection of hearing protectors.

The monitoring requirement is performance based, as it allows employers to choose a monitoring method that best suits each individual work situation. Either personal or area monitoring may be used. If there are circumstances that may make area monitoring generally inappropriate, such as high worker mobility, significant variations in sound level or a significant component of impulse noise, then the employer must use representative personal sampling unless it can be shown that area sampling produces equivalent results.

Noise measurements must integrate all continuous, intermittent, and impulsive noise levels from 80 to 130 decibels. (Note: A July 30, 2025, OSHA letter of interpretation answers questions about impact/impulse noise that exceeds 140 decibels.) Monitoring must be repeated whenever a change in production, process, equipment or controls increases noise exposures to the extent that additional employees may be exposed at or above the action level, or the attenuation provided by hearing protectors used by employees is inadequate.

The employer must notify each employee who is exposed at or above the action level of the results of the monitoring and provide them with an opportunity to observe noise monitoring procedures.