Hearing Flashcards
What are the two basic functions of hearing?
To detect any vibrations in the air
Responsible for balance and sensing acceleration
What are the three divisions of the ear?
Outer ear
Middle ear
Inner ear
Describe the outer ear
It directs sound down the auditory canal and onto the eardrum
Describe the middle ear
Beyond the eardrum
Vibrations from eardrum transmit to 3 bones called ossicles
What are the names of the ossicles?
Hammer
Anvil
Stirrup
Describe the inner ear
Filled with fluid
Connected to the cochlea which has basilar membranes that detect movement that sends signals to the brain
How does air refresh in the ear?
Through the eustachian tube
Which regulation replaced the Noise at Work Regulations 1989?
The control of noise at work regulations 2005
What is the aim of the Noise Regulation?
To ensure the workers hearing is protected from excessive noise, which could cause them to lose their hearing or to suffer from tinnitus
When did the noise regulations come into full force for all industry sectors in GB?
April 6th 2006
How does the middle ear protect against sounds above 80dB?
Two muscles activating the acoustic/aural reflex which reduces sounds by up to 20dB
Where is the Basilar Membrane found?
In the Cochlea
What is the Exposure Limit value of 87dB?
The level that must not be exceeded when wearing hearing protection
What will the employer do if the noise level at the ear reaches 87dB, taking account of any reduction in noise level?
Work must cease until a solution is provided to reduce the exposure level to below 87dB
What is noise induced hearing loss?
Reduced hearing ability due to exposure of noise
Can be temporary or permenant
What is a noise dose?
The combination of duration and intensity of noise
By how many decibels does the sound constitute a noise dose?
over 80dB
What is Time Weighted Average Sound level
Used to calculate a workers daily exposure to noise , taking into account the daily or weekly exposure
What is the typical audio range for a young person?
20-20000 Hz
What is the required level at which the employer must provide hearing protection and hearing protection zones?
85dB or more on a daily and weekly average exposure
If normal speech cannot be heard at 1 meter
What is the required level at which the employer must assess the risk to worker’s health and provide them with information and training?
80dB or over
If speech cannot be heard at 2 meters
What is the term used to describe hearing that is naturally deteriorating?
Presbycusis
