The Complete Guide to OSHA's Hearing Conservation Standard (29 CFR 1910.95)

The Occupational Safety and Health Administration's Hearing Conservation Standard (29 CFR 1910.95) is the regulatory backbone of workplace hearing protection in the United States. If your employees are exposed to noise levels at or above 85 decibels averaged over an 8-hour workday, you're required to have a hearing conservation program in place.

Yet despite being one of the most commonly cited OSHA standards, many employers still struggle with full compliance. In this guide, we'll break down every key requirement and explain how to build a hearing conservation program that not only meets OSHA standards but genuinely protects your workers' hearing.

Who Must Comply?

The hearing conservation standard applies to all general industry employers (covered under 29 CFR 1910) whose workers are exposed to noise at or above the Action Level — an 8-hour Time Weighted Average (TWA) of 85 dB. This is distinct from the Permissible Exposure Limit (PEL) of 90 dB TWA, which triggers additional engineering and administrative controls.

Industries with the highest noise exposure rates include:

• Manufacturing (machinery, assembly lines, stamping plants)
• Construction (though covered under a separate standard, 1926.52)
• Mining operations
• Oil and gas extraction
• Entertainment venues and music production
• Transportation and warehousing
• Agriculture

The Seven Components of a Hearing Conservation Program

1. Noise Monitoring

Employers must conduct noise monitoring when there's reason to believe any employee's exposure may meet or exceed the 85 dB action level. Monitoring can be done via area surveys (using sound level meters) or personal dosimetry (attaching a noise dosimeter to individual workers).

Monitoring must be repeated whenever changes in production, equipment, or processes could increase noise levels. Employees must be notified of monitoring results and given the opportunity to observe monitoring procedures.

2. Audiometric Testing

This is where most of the ongoing compliance work happens. Every employee in the hearing conservation program must receive:

• Baseline audiogram: Within 6 months of first exposure (or 12 months if a mobile testing van is used, provided the employee wears hearing protection in the interim)
• Annual audiogram: Every year thereafter, compared against the baseline to detect Standard Threshold Shifts (STS)

Audiograms must be performed by a licensed or certified audiologist, otolaryngologist, or a technician certified by CAOHC (Council for Accreditation in Occupational Hearing Conservation).

3. Standard Threshold Shift (STS) Detection

An STS is defined as an average shift of 10 dB or more at 2000, 3000, and 4000 Hz in either ear, relative to the baseline. When an STS is detected:

• The employee must be notified in writing within 21 days
• Hearing protector use must be re-evaluated and refitted if necessary
• The employee must be referred for a clinical audiological evaluation if indicated
• The employer must determine if the STS is also OSHA recordable (if the STS brings the average threshold at 2K/3K/4K to 25 dB or above)

Age correction: OSHA allows employers to apply age correction factors from Table F-1 when calculating STS. This accounts for presbycusis (age-related hearing loss) and can reduce false-positive STS determinations.

4. Hearing Protectors

Employers must make hearing protectors available at no cost to all employees exposed at or above the action level. Protectors are mandatory for employees who have experienced an STS, or who are exposed at or above the PEL (90 dB TWA).

The employer must ensure that hearing protectors provide adequate attenuation — reducing the employee's effective exposure below 90 dB (or below 85 dB for those with a confirmed STS).

5. Training

Annual training must cover:

• The effects of noise on hearing
• The purpose, advantages, and proper use of hearing protectors
• The purpose and procedures of audiometric testing

6. Recordkeeping

Employers must maintain:

• Noise exposure measurements for at least 2 years
• Audiometric test records for the duration of employment, including employee name, job classification, date of test, examiner's name, audiometer calibration date, and all threshold measurements

These records must be made available to employees, former employees, and OSHA upon request.

7. Program Evaluation

While not explicitly called out as a separate requirement, effective hearing conservation programs include regular evaluation of their effectiveness — tracking STS rates across the organization, reviewing hearing protector attenuation, and adjusting the program as needed.

Common Compliance Pitfalls

These are the most common compliance mistakes in hearing conservation programs:

• Overdue baseline audiograms: New employees not tested within the required timeframe
• Missed annual tests: Employees falling through the cracks, especially in organizations with high turnover
• Late STS notifications: Missing the 21-day notification window after STS detection
• No baseline revision: Failing to evaluate whether a persistent STS should trigger a baseline revision
• Inadequate recordkeeping: Using paper records or spreadsheets that are prone to loss and difficult to search
• Recordability misses: Not evaluating whether an STS meets the 25 dB threshold for OSHA 300 log recording

How Software Can Help

Modern hearing conservation software like AudiVault can automate many of the compliance-critical workflows:

• STS calculation: Automatic comparison against baselines with age correction applied
• Notification tracking: Automated generation of OSHA notification letters with 21-day deadline tracking
• Annual test scheduling: Dashboard showing which employees are due for testing
• Recordability determination: Automatic flagging when an STS meets OSHA 300 log criteria
• Audit trail: Immutable logs of all actions for OSHA inspections
• Cloud-based records: Secure, searchable audiometric records that meet retention requirements