Fletcher Munson Curve Research Paper
Fletcher Munson Curve (Equal Loudness Contour)
Sound is our brains interpretation of the changes in air pressure
Our ears are so sensitive that they can detect the sound generated my a mosquito’s wing 10 feet away (which is roughly 0dB)
120dB (threshold of pain) is 1,000,000,000x (trillion) more powerful than 0dB
The Fletcher Munson Curve was discovered in the early 1930s when a phone company wanted to find the least expensive way to transmit a phone call by using the least amount of energy
Our ears hear 2kHz as being louder than 1kHz even when at the same dB. This means that it requires less energy to hear 2kHz frequencies
Our ears are most sensitive to hearing 3.5kHz as this is the resonance frequency of our ear canals
Range of frequencies …show more content…
we are sensitive to are between 1kHz and 5kHz (this is the frequency range that mobile phones play out)
We hear low and high frequencies very poorly
The 90dB reference curve is the most flat, meaning that most frequencies appear to be at the same level. This is why music sounds a lot better and more full when played loudly around this frequency
Summary
Equal Loudness Contours show the measure of sound pressure levels in relation to different frequencies. Our ears perceive different frequencies of sound to be louder or quieter than each other even when played at the same reference level of dB.
Hearing Damage
Tinnitus (both temporary and permanent)
Tinnitus is a term used to describe the case of being able to hear sounds that are within the person’s body, rather than sounds from an outside source.
It often causes a ringing in the ears, but other sounds that can be heard include humming, buzzing and whistling. Tinnitus can either be caused by a build up of earwax, a mild ear infection, or also very commonly can be caused by damage to the inner ear from loud noises (usually high frequencies).
Tinnitus can be prevented by best by avoiding exposure to loud noises completely, however this can prove difficult in a lot of scenarios. A more realistic approach to preventing tinnitus include reducing the time that you are exposed to loud noises, this can be done by either spending less time in noisy environments, or by taking regular breaks about every half hour for ten minutes or so. Another way to reduce the risk of getting tinnitus is by ensuring that you stay hydrated, as this makes sure that the circulation for the blood in the inner ear is kept ‘topped up’.
You can also reduce the risk of getting tinnitus by reducing the intensity of exposure. Either turning the volume down yourself can do this, or if you don’t have control of the volume, then you can wear
earplugs.
Noise Induced Hearing Loss (both temporary and permanent)
Noise Induced Hearing loss (NIHL) is caused by either very loud noises for either a brief or prolonged time. The loud sounds can damage sensitive structures in the inner ear and can result in struggling or being unable to hear certain frequencies, or just partially deafening your ear(s).
NIHL can be prevented in the same ways as tinnitus and most other hearing problems. If you reduce the amount of time you are exposed to loud noises, or reduce the intensity of the noise by wearing ear protection, then you are reducing the risk of damaging your ears either temporarily or permanently.
Sound is our brains interpretation of the changes in air pressure
Our ears are so sensitive that they can detect the sound generated my a mosquito’s wing 10 feet away (which is roughly 0dB)
120dB (threshold of pain) is 1,000,000,000x (trillion) more powerful than 0dB
The Fletcher Munson Curve was discovered in the early 1930s when a phone company wanted to find the least expensive way to transmit a phone call by using the least amount of energy
Our ears hear 2kHz as being louder than 1kHz even when at the same dB. This means that it requires less energy to hear 2kHz frequencies
Our ears are most sensitive to hearing 3.5kHz as this is the resonance frequency of our ear canals
Range of frequencies …show more content…
we are sensitive to are between 1kHz and 5kHz (this is the frequency range that mobile phones play out)
We hear low and high frequencies very poorly
The 90dB reference curve is the most flat, meaning that most frequencies appear to be at the same level. This is why music sounds a lot better and more full when played loudly around this frequency
Summary
Equal Loudness Contours show the measure of sound pressure levels in relation to different frequencies. Our ears perceive different frequencies of sound to be louder or quieter than each other even when played at the same reference level of dB.
Hearing Damage
Tinnitus (both temporary and permanent)
Tinnitus is a term used to describe the case of being able to hear sounds that are within the person’s body, rather than sounds from an outside source.
It often causes a ringing in the ears, but other sounds that can be heard include humming, buzzing and whistling. Tinnitus can either be caused by a build up of earwax, a mild ear infection, or also very commonly can be caused by damage to the inner ear from loud noises (usually high frequencies).
Tinnitus can be prevented by best by avoiding exposure to loud noises completely, however this can prove difficult in a lot of scenarios. A more realistic approach to preventing tinnitus include reducing the time that you are exposed to loud noises, this can be done by either spending less time in noisy environments, or by taking regular breaks about every half hour for ten minutes or so. Another way to reduce the risk of getting tinnitus is by ensuring that you stay hydrated, as this makes sure that the circulation for the blood in the inner ear is kept ‘topped up’.
You can also reduce the risk of getting tinnitus by reducing the intensity of exposure. Either turning the volume down yourself can do this, or if you don’t have control of the volume, then you can wear
earplugs.
Noise Induced Hearing Loss (both temporary and permanent)
Noise Induced Hearing loss (NIHL) is caused by either very loud noises for either a brief or prolonged time. The loud sounds can damage sensitive structures in the inner ear and can result in struggling or being unable to hear certain frequencies, or just partially deafening your ear(s).
NIHL can be prevented in the same ways as tinnitus and most other hearing problems. If you reduce the amount of time you are exposed to loud noises, or reduce the intensity of the noise by wearing ear protection, then you are reducing the risk of damaging your ears either temporarily or permanently.