CSA Z107.56 and worker audiometric testing basics

Hearing loss caused by workplace noise often develops gradually, making it difficult for workers and employers to identify the problem without reliable measurements. A structured hearing conservation program connects noise surveys, employee education, hearing protection, and audiometric testing.

CSA Z107.56 is primarily concerned with procedures for measuring occupational noise exposure. These measurements help determine whether workers may be exposed to hazardous sound levels and whether a hearing conservation program requires additional controls. Audiometric testing complements the standard by showing whether a worker’s hearing has changed over time.

The applicable edition, provincial requirements, workplace conditions, and industry rules should always be reviewed before a program is designed. A purchased digital copy of the current standard can give safety professionals and occupational health providers direct access to the technical requirements they need.

What the standard addresses

CSA Z107.56 provides a consistent approach to evaluating occupational noise exposure. It supports measurements taken with sound level meters, personal noise dosimeters, and related equipment, depending on the work activity and the question being investigated.

The purpose is to produce dependable exposure data rather than an isolated sound reading. Noise can vary by task, shift, location, equipment condition, and worker movement. A suitable measurement strategy captures these variations and helps identify which employees or job groups need further protection.

The standard is therefore closely connected to hearing conservation, although it should not be treated as a complete audiometric testing protocol. Noise exposure assessment identifies the risk; hearing tests help monitor the effect of that risk on individual workers.

How noise measurement supports audiometry

Audiometric testing establishes a worker’s hearing thresholds at selected frequencies. A baseline test provides a point of comparison, while later tests may reveal a threshold shift that requires evaluation. Accurate exposure measurements help determine how frequently testing should occur and which work groups require priority attention.

Testing should be performed by appropriately qualified personnel using calibrated audiometric equipment and controlled procedures. Workers may need a suitable quiet period before testing so that temporary hearing changes caused by recent noise exposure do not distort the results. Local legislation and occupational health guidance determine the precise program requirements.

A noise survey can also show whether hearing protection is being used in the right locations. If measurements indicate excessive exposure, an employer may need to improve engineering controls, reduce exposure time, redesign work practices, or select more effective hearing protection rather than relying on audiometry alone.

Essential technical considerations

Reliable results depend on planning. The person conducting the assessment should understand the work process, identify representative tasks, note unusual noise events, and select equipment appropriate for the sound environment. Instruments require calibration and functional checks according to the manufacturer’s instructions and the applicable standard.

Personal dosimetry is useful when a worker moves between areas or performs several tasks during a shift. Area measurements may be appropriate for mapping noise sources, evaluating specific machinery, or comparing locations. Neither method should be selected automatically; the measurement approach should reflect the exposure being evaluated.

Records should identify the worker or job group, measurement date, tasks observed, instruments used, calibration information, sampling duration, and relevant environmental conditions. Clear documentation allows later reviewers to understand how the result was obtained and whether it remains representative.

Program element	Main purpose	Typical output
Noise survey	Identify sound sources and exposed areas	Area readings and task profiles
Personal dosimetry	Estimate an individual worker’s shift exposure	Time-weighted exposure record
Audiometric test	Monitor hearing thresholds over time	Baseline and follow-up audiograms
Hearing protection review	Check whether protection matches the hazard	Selection and fit recommendations
Program evaluation	Determine whether controls are working	Corrective actions and trend analysis

Understanding exposure results

Noise exposure results must be interpreted against the legal limits and action levels that apply in the jurisdiction. A measurement may indicate that a worker’s exposure is acceptable under one rule but requires action under another. For this reason, CSA Z107.56 should be used together with current occupational health and safety legislation.

Results also need context. A shift with unusually loud maintenance work may not represent normal conditions, while a quiet sampling day may underestimate routine exposure. Repeated surveys can help confirm trends, especially after equipment changes, process expansion, or complaints about noise.

Employers should communicate results in practical terms. Workers need to know which tasks create the greatest risk, when hearing protection is mandatory, how to wear it correctly, and why audiometric follow-up matters. Technical reports are most valuable when they lead to understandable workplace controls.

Connecting testing with a hearing conservation program

A complete program usually combines noise assessment, worker training, access to suitable hearing protectors, audiometric monitoring, recordkeeping, and corrective action. The order matters: exposure controls should be considered at the source and along the path before personal protective equipment becomes the only measure.

Audiometric results should be reviewed by qualified health professionals under applicable privacy and medical-record requirements. A possible threshold shift does not automatically prove that workplace noise caused hearing loss. It may require retesting, clinical assessment, review of test conditions, and examination of occupational and non-occupational noise history.

Employers can use group trends to evaluate program effectiveness without exposing confidential medical information. Rising hearing threshold changes in a department may signal inadequate controls, inconsistent protector use, poor fit, or limitations in the testing process.

Purchasing and applying the right edition

Standards are periodically revised to reflect updated terminology, measurement practices, and technical expectations. Before relying on a copy, verify its designation, publication year, amendment status, and relationship to the regulations governing the workplace. A current edition is especially important when a company is preparing an audit, updating a safety program, or comparing contractor requirements.

Document Bays provides access to downloadable technical standards for engineering, safety, manufacturing, and compliance work. Keeping the relevant CSA document available to safety managers, industrial hygienists, and auditors can simplify consultation during surveys and program reviews.

Practical steps for implementation

A workplace beginning or improving its hearing conservation process can focus on these actions:

• Identify noisy tasks, equipment, departments, and work shifts before selecting a sampling method.
• Use calibrated instruments and document the sampling plan, conditions, and observed activities.
• Compare exposure results with the correct provincial or federal requirements.
• Schedule baseline and periodic audiometric testing through qualified occupational health personnel.
• Review trends and investigate potential threshold shifts promptly, while protecting worker confidentiality.

CSA Z107.56 is most useful when treated as part of a connected risk-management process. Obtain the applicable edition, align its measurement procedures with local law, and use the resulting evidence to strengthen noise controls and worker hearing protection.