Anatomy of the Ear

Every single structure has a specific purpose
Every single structure has a specific purpose
An area not covered in this picture is the:
external or outer ear, which is made of:
pinna or auricle - the outside part of the ear. Its unique shape helps sound waves travel into the ear canal.

-external auditory canal or tube - the tube that connects the outer ear to the inside or middle ear.

-tympanic membrane - a.k.a. the eardrum. This divides the external ear from the middle ear.
middle ear (tympanic cavity), which is made of:
-ossicles - three small bones which are connected and also transmit the sound waves to the inner ear. The bones are called:
  • The malleus
  • The incus
  • and the stapes

eustachian tube - This canal links the middle ear with the throat region part. It helps equalize the pressure between the outer ear and the middle ear. Having equal pressure allows for the transfer of sound waves properly. The eustachian tube is lined with mucous, just like the inside of the nose and throat.
(Fun fact- without mucous, you stmoach would digest itself)
  • inner ear, made of:

    • cochlea (has the nerves for hearing)
    • vestibule (has receptors for balance)
    • semicircular canals (also has receptors for balance)

Anatomy of the Signal

If you break down sound waves and their process of travel you'll realize that its the air molecules that are transfering kinetic energy

external image PSM_V13_D058_Sound_waves_1.jpg
Its through the transference of kinetic energy from the air moleciules that allow us to hear and also interprete the origin of the signal.
Noise has as much variety as the sounds made by this electro-acoustic guitar
Noise has as much variety as the sounds made by this electro-acoustic guitar

Frequency Wavelength and Amplitude

These three terms are what seperates the sound of a bird chirping from the sound of a car engine. However, there are sounds that are beyond human detection either because they are too low or too high for us to hear. "Infrasound" are low frequency sounds that are beyond the range of hearing for people. "Audio frequencies" are sounds that can be heard. "Ultrasound" consists of very high frequencies, nut are also beyond the human range of hearing like sonar.

external image Cochlea_wave_animated.gif
Frequency- Is the number of cycles per a unit of time. An example is in music; 40 Beats per Minute. Another example is strobe lights and how you can adjust the number of times it can flash for every second. The unit of measurement for frequency is the hertz (Hz), which means cycles per second.

Wavelength- This is the distance between every one wave. Wavelengths in sounds are much longer than those in light (infra-red, UV, etc.)

Amplitude- Is the height of the wave and effects the intensity of the sound that is being produced.

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