Changes in hearing acuity in ambulance personnel

Area of Science:

• Occupational Health
• Audiology
• Emergency Medical Services

Background:

• Emergency medical services (EMS) personnel, including emergency medical technicians (EMTs) and paramedics, operate in noisy environments.
• Occupational noise exposure is a known risk factor for hearing loss.
• Understanding the impact of ambulance noise on hearing is crucial for protecting EMS professionals.

Purpose of the Study:

• To assess whether EMTs and paramedics experience excessive hearing loss due to occupational noise exposure.
• To measure noise levels within a modern ambulance during an eight-hour shift.

Main Methods:

• Retrospective analysis of audiograms from 81 EMTs and paramedics.
• Calculation of age-adjusted threshold shifts at specific frequencies (1,000, 2,000, 3,000, and 4,000 Hz).
• Correlation of threshold shifts with elapsed time and measurement of in-ambulance noise levels.

Main Results:

• No significant correlation was found between elapsed time and age-adjusted threshold shifts at any tested frequency or ear.
• Ambulance noise levels ranged from 58 dBA (stationary patient compartment) to 84 dBA (forward cab with windows down and siren active).
• Measured noise levels remained below Occupational Safety and Health Administration (OSHA) exposure limits.

Conclusions:

• Ambulance personnel do not exhibit excessive hearing loss attributable to their occupation.
• Noise levels within the studied ambulance are not considered hazardous according to OSHA standards.
• Further research may explore long-term effects or specific high-noise event impacts.