Hearing loss due to noise is a big problem for all pilots and flight instructors, especially those flying small aircraft. Think about it: everyday, after flight, the pilot receives certain scratches from the engine, exhaust, propeller, fuselage and other areas. Also, unlike other noisy occupations, pilots are generally exposed to the same noise frequency and intensity over a long period of time. Please tell me important things to know about noise fatigue and how to prevent long-term hearing impairment.
Noise fatigue is a health problem for all pilots, but small airplanes, especially turboprops, generally have less noise and poor thermal insulation compared to large commercial jet aircraft. Even if you fly a larger aircraft with the interior of Khmer, there is a possibility that the cabin door is open and you are exposed to the surrounding noise from taxis and cockpits. Most noise in and around the aircraft is in four main areas:
- Normally the noise from the exhaust stack (especially short stack) located directly under the cabin and the resulting airflow are pushed up to the bottom of the fuselage
- Propeller airflow against propeller and windshield
- Air flow through the vent, leak around the door, turbulence through the fuselage
- Engine noise, especially vibration of air-cooled engine
Average decibel level
Decibel (dB) is the unit used to measure sound intensity. In order to know the average decibel level of daily sounds, consider the following points.
- Whisper - 30 dB
- Quiet room - 40 dB
- Normal conversation - 60 dB
- Busy traffic - 70 dB
- Gas lawnmower - 106 dB
- Jack Hammer - 130 dB
- Jet engine - 140 dB
Keep in mind that hearing impairment may result from permanent hearing impairment from sounds above 85 dB, physical pain at about 125 dB, and the eardrum may explode at 140 dB. The Occupational Safety and Health Organization (OSHA) states that the maximum level of "safe" exposure to loud sounds is 90 dB for up to 8 hours, 100 dB for up to 2 hours. At OSHA, workers with noise levels above 85 dB must use hearing protection equipment.
Study on noise level of aircraft
In 2010, an occupational safety and health survey entitled "Noise Level in the General Aircraft" was conducted to determine whether long-term exposure to the noise of indoor aircraft is a health hazard for the pilot It was done.
For the study, sound samples were taken with Cessna 172 and Piper PA-44 Seminole - two planes on different aircraft. While the airplane was flying, the two volumeters read the idea of the true noise level from within the passenger's headset as well as the surrounding noise from the cabin, without hearing protection.
In order to simulate the "worst plane day scenario" the researchers tested the 8 hour exposure and created a time weighted average of 8 hours from the sound sample reading. The time weighted average of all aircraft cabin measurements was 86.26 dBA. The data of this study highlighted that the pilots are indeed exposed to higher levels than the OSHA standards. In this investigation, the use of the headset was judged to be appropriate hearing protection for the planned 8 hours. Read complete research. In order to know the decibel level inside the aircraft, I purchase a decibel meter at the electrical equipment shop, and acquire the reading values during climbing, cruising, and descent (unfortunately). Please note that the dB level inside the headphone must be lower than the unprotected noise level around the cockpit and cabin.
Tips for protecting your ears
If the ambient noise level in the cockpit reaches 90 dBA, you must use hearing protection equipment. If the noise level of the cockpit exceeds the OSHA exposure limit, an excellent set of headsets is essential. Active noise reduction heads are recommended to improve signal-to-noise ratio and sound quality. Another advantage of quality headsets is to reduce high frequency background noise and make the audio signal clearer and easier to understand. To achieve maximum protection, use an active noise reduction headset in combination with an earplug. Another good tip is to restrict exposure to noisy activities before flying, such as mowing the lawn or listening to loud music.
If you have symptoms of hearing impairment ...
For some symptoms of hearing loss, it is difficult to listen to television and music at a loud volume, frustrate listening, and avoid social interaction. Exposure to loud volume or undetected hearing impairment may cause hypersensitivity, lack of concentration, hypertension, elevated stress levels, insomnia, heart rate abnormality or abnormality.
If you are suspected of suffering from hearing disorder or side effects, consult a doctor and have the qualified otologist or auditor undergo an inspection, if there is a possibility of hearing impairment investigate it, treat can.
