Personal noise dosimetry measures the sound exposure an employee actually receives while moving through a normal work shift.
On-Site Acoustic Testing provides occupational noise exposure surveys and personal noise dosimetry for industrial, manufacturing, commercial and other workplaces. Dosimetry is particularly useful when employees move between work areas, operate different equipment, or experience changing noise levels that cannot be characterized adequately by a few stationary sound-level measurements.
OSHA Personal Noise Exposure Measurements
For OSHA general-industry evaluations, 29 CFR 1910.95 establishes an 8-hour permissible exposure limit (PEL) of 90 dBA using a 5 dB exchange rate. A continuing hearing-conservation program is required when employee exposure equals or exceeds an 8-hour TWA of 85 dBA, the OSHA action level. The applicable measurement settings and criteria depend on the purpose of the survey and the regulatory or project requirements.
Planning an Occupational Noise Survey
Before fieldwork, it is helpful to identify the job groups to be evaluated, typical shift lengths, the operations performed during each shift, and any unusual or intermittent high-noise tasks. Existing exposure data, hearing-conservation documentation, and a description of the applicable OSHA or project criteria can help establish a representative sampling plan. OSAT can coordinate with the facility to minimize disruption while documenting the conditions under which measurements are taken.
Full-Shift Noise Dosimetry
A personal dosimeter is worn near the employee’s hearing zone while normal work activities are performed. Full-shift sampling can document time-weighted average exposure and accumulated noise dose while capturing the changing conditions encountered throughout the workday.
Shorter samples can be useful for screening or investigating particular tasks, but extrapolation requires the sampled period to be representative of the employee’s actual exposure. Where compliance documentation is the objective, the sampling strategy is selected accordingly.
Casella dBadge2 Personal Noise Dosimeters
OSAT uses Casella dBadge2 personal noise dosimeters for current occupational-noise surveys. Modern dosimeters can record multiple exposure parameters during the same measurement period, allowing the collected data to be evaluated using the criteria appropriate to the project.
Noise Exposure Reports and Follow-Up Testing
Results can include measured TWA, noise dose, peak levels and time-history information as appropriate to the survey. Where elevated exposures or specific noisy operations are identified, dosimetry can be supplemented with sound-level and frequency-spectrum measurements to help characterize the contributing sources and evaluate potential noise-control measures.
OSAT can also support broader OSHA noise consulting and industrial noise testing requirements.
Extended Shifts and Representative Exposure
For employees working 10-hour, 12-hour or other nonstandard shifts, the survey should document actual shift duration, tasks and exposure patterns. OSAT can report measured dose and time-weighted exposure using the selected regulatory criteria, with any normalization or extended-shift interpretation clearly identified. OSHA and NIOSH use different exchange rates and assessment criteria; results should not be treated as interchangeable.
Hearing Protection and Exposure Assessment
Measured exposure data can support review of hearing-protector suitability, including the manufacturer’s Noise Reduction Rating (NRR), the applicable OSHA attenuation evaluation method and practical workplace considerations. A published NRR alone does not establish the attenuation achieved by an individual worker. Where appropriate, OSAT can identify exposures that warrant additional hearing-protection evaluation or coordination with the employer’s occupational-health provider.
Workplace Noise Mapping and Source Identification
Personal dosimetry may be supplemented with targeted measurements of machinery, processes and work areas. Where facility drawings and sufficient measurement coverage are available, area sound levels can be presented on a facility plan to identify higher-noise zones and help prioritize engineering or administrative controls. Such maps represent the measured conditions and do not replace individual exposure dosimetry.
Clear, Actionable Occupational Noise Reporting
Depending on project scope, reports can include employee or job-group exposure tables, measured TWA and dose, relevant OSHA criteria, time-history observations, significant noise sources and locations, and prioritized follow-up recommendations. Reports can identify measured exposures at or above the OSHA hearing-conservation action level and highlight possible compliance gaps for the employer’s review. The employer remains responsible for determining and implementing its regulatory obligations.
Hearing Conservation Program Support
Exposure surveys provide a technical foundation for an employer’s hearing conservation program. OSAT can support noise monitoring, identification of affected employee groups, evaluation of potential noise controls and documentation of measurement findings. Audiometric testing, clinical interpretation and medical oversight are separate occupational-health services performed by appropriately qualified providers. See our hearing conservation assessment page for additional context.
Discuss Your Workplace Noise Survey
Contact On-Site Acoustic Testing with the facility location, employee work patterns, shift duration and reason for testing so an appropriate measurement plan can be developed.