Speech Science, Exam 1
Terms
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- Acoustic Reflex
- Middle ear relfez that attenuates intense sounds of 80 dB or more. aka stapedial reflex
- Basilar Membrane
- Base of the cochlear duct; basal portion nearest the typanic membrane is narrow and stiff, with membeane becoming wider and more compliant toward the apical portion farthest from the TM
- Cerumen
- Waxy substance produced in the external auditory meatus
- Cochlea
- Snail-shaped spiral canal housing the nerve receptors for hearing
- Cochlear Duct
- structure that divides the cochlea along most of it's length; aka cochlear partition
- Conductive Hearing Loss
- HL caused by problems in the transmission of sound to the inner ear
- External Auditory Meatus
- channel leading from the pinna to the TM; aka ear canal
-
Imdedance
Imbedance mismatch -
measure of the opposition of a system to a flow of energy through it, measured in ohms.
difference in impedance between two mediums - ossicles
-
Malleus--touches TM
Incus
Stapes--touches OW - Organ of Corti
- sensory nerve receptor for hearing, consisting of rows of inner and outer hair cells
- Compare the functions of the ear canal and the TM
-
Ear canal: protects middle ear. is 1/4 wave resonator, important in sound detection, boosts amplitute of high frequency sounds.
TM: transduces sound energy to mechanical energy - oval window
- Stapes makes contact here to transmit mechanical wave into cochlea.
- round window
- opening between the scala tympani and the middle ear, covered with membrane
- sensorineural HL
- HL due to disease or damage to the inner ear or auditory nerve
- Describe structure of middle ear and how it overcomes the impedance mismatch
-
TM->Malleus/incus/stapes->OW
Increase FORCE at stapes x1.3, area ratio 17:1 from TM to OW = more PRESSURE - tonotopic organization
- spatial organization of the basilar membrane in terms of frequency distribution
- transduction
- changing energy from one form (medium) to another
- Discuss the funtions of the cochlea as it relates to the tonotopic theory
- lower f's activate nerves at apex, higher f's activate nerves at base due to tonotopic organization
- vestibular memberane
- roof of the cochlear duct
- Function of the organ of corti
- contains hair cells embedded in basilar membrane. transmits sound into electrical impulses as BM vibrates and stimulates HC's
- Role of the Vestibular System
- monitors position of head in space. helps with balance control
- How the VIII cranial nereve travels to the Auditory Complex
- cochlea->
- Where does decussation take place in the Brain Stem for the auditory fibres
- between Pons and Medulla
- Function of Outer and Middle ears
- To boost sound signal and overcome impedance mismatch
- amplitude
- amount of displacement off an object from its rest position
- aperiodic
- wave in which cycles do not take the same amount of time to occur
- attenuation rate
- rate in dB per octave at which a resonator's amplitute of response is attenuated
- bandwidth
- range of f'd that a resonator will transmit
- boyles law
- states that a dry gas's volume varies inversly with pressure, given a constant temperature
- broadly tuned
- resonator that transmits a wide range of frequencies
- cgs system
- system of measurement using centimeters, grams, and seconds. Dynes is in this system
- complex sound
- sounds with two or more f's
- cut-off frequency
- F(sub)c, f at which a resonant system is unresponsive
- damping
- decreasing in amplitude
- dyne
- unit of measure of force and pressure in cgs system
- elasticity
- restorying frce that brings an object back to its orginal size, shape, or position after having been displaced or deformed
- fourier analysis
- mathematical procedure to identitfy the individual sinusoids in a complex sound
- frequency
- rate of vibration of an object
- volume velocity
- aka rate of flow
- waveform
- graph with time on x axis and amplitude on y axis
- fundamental frequency
- lowest frequency of a complex periodic sound
- harmonics
- frequencies above Fo in a complex periodic sounds
- inertia
- tendency of matter to remain at rest or in motion uless acted on by an outside force
- interference
- combining of waved in terms of areas of high ans low pressure
- microbar
- measurement of dynes/cm2
- pascal
- unit of measure of pressure in the modernized metric system
- period
- amount of time it takes for a cycle of a wave to complete itself
- pure tone
- sound with only one frequency componant
- rarefaction
- area of negative pressure in a sound wave traveling through a medium
- Describe how elasticity and inertia interact to maintain vibrations, and then what happens when damping occurs
- inertia keeps molecules moving once they are struck, and elasticity tries to restore them to to starting position. as molecules move back to rest, they overshoot spot due to inertia of motion it took to move back there. Back/forth motion decreased in amplitude due to damping
- Explain how pharynx->nose structures impact resonance in the human voice
- Irregularly shaped resonators are broadly tuned and heavily damped, so many freqencies are allowed and sounds can change quickly
- What is the relationship between frequency and pitch?
- Frequency is measured in cycles/sec and is a physical measurement. Pitch is the psychoacoustical interpretation of frequency.