Task 7 Good vibrations Flashcards
Fourier analysis
- Method to show level of frequency
* A combination of tones form a complex sound
Rare fraction
back and forth movement of the pressure change, molecules go back and forth
Amplitude or intensity
The magnitude of displacement (increase or decrease) of a sound pressure wave. Amplitude is perceived as loudness
Frequency
For sound, the number of times per second that a pattern of pressure change repeats. Frequency is perceived as pitch
Hertz (Hz)
A unit of measure for frequency. One hertz equals one cycle per second
Decibel (dB)
A unit of measure for the physical intensity of sound. Decibels define the difference between two sounds as the ratio between two sound pressures. Each 10:1 sound pressure equals 20 dB and a 100:1 ratio equals 40 dB
o An increase of 6 dB correspond to a doubling of the amount of pressure
Sine wave or pure tone
The wave form for which variations as a function of time is a sine function
Spectrum
A representation of the relative energy (intensity) present at each frequency
Harmonic spectrum
A complex sound which is a multiple (40, 80, 120) of the fundamental frequency (often caused by instruments)
Fundamental frequency
The lowest-frequency component of a complex sound
Fundamental missing
we would still hear the fundamental frequency when its nit present
Outer ear
the external sound gathering portion of the ear consisting of the pinna and the ear canal
Pinna
the outer, funnel-like part of the ear, sounds are collected from the environment
Ear canal
: the canal which receives bundled vibrations from the pinna and conducts them to the tympanic membrane and prevents damage to the tympanic membrane
Tympanic membrane
Ear drum, a thin sheet of skin at the end of the outer ear canal. The tympanic membrane vibrates in response to sound
Middle ear
An air-filled chamber containing the middle bones or ossicles. The middle ear conveys and amplifies vibration from tympanic membrane to the oval window
Ossicle
Three tiny bones that amplify sound waves
Malleus: Receives input from the tympanic membrane and is attached to the incus
Incus: connecting malleus and stapes
Stapes: Connected to the incus on one end and, the stapes presses against the oval window of the cochlea on the other end
Oval window
The flexible opening to the cochlea through which the stapes transmits vibration to the fluid inside. Border between middle and inner ear
Tensor tympani
The muscle attached to the malleus, tensing the tensor tympani decreases vibration
Stapedius
The muscle attached to the stapes tensing the stapedius decreases vibration
Inner ear
A hollow cavity in the temporal bone of the skull and the structure within this cavity: The cochlea and the semi-circular canals of the vestibular systems
Cochlea
A spiral structure of the inner ear containing the organ of Corti, is filled with water like fluid in the three parallel canals
Tympanic canal: One of the three flud filled passages in the cochlea. The tympanic canal extends from the round window at the base of the helicotrema at the apex
Vestibular canal: extends from the oval window at the base of the cochlea to the helicotrema at the apex
Middle canal: The middle canal is sandwiched between the tympanic and vestibular canals and contains the cochlear partition