Auditory Perception Flashcards
(41 cards)
What is the speed of sound in air, water and glass?
Air - 340 ms
Water - 1500 ms
Glass - 5300 ms
What is the speed of light in air?
300,000 km/s
What is sound?
Sound refers to pressure waves generated bu vibrating air molecules.
It has the effect of a vibrating speaker on the surrounding air producing regions of condensation and rarefaction. Like when a pebble is dropped in water.
What are sound waves 2 basic features?
Frequency (pitch, Hz) and Amplitude (loudness, dB)
What are pure tones?
Sounds that consist of a sine wave.
What 2 things are sounds made of?
One fundamental frequency and several harmonics of the fundamental.
What decibel and relative amplitude can cause damage to the hear receptors?
120dB and relative amplitude of 1,000,000.
What range does the human audible system range from?
20 to 20,000Hz.
When is sound sensitivity greatest in the human audible spectrum?
between 500 to 5000Hz which includes the range of speech sounds and music.
What frequency do smaller animals tend to hear? Why is this?
Higher frequencies because the cochlea of smaller animals is smaller and reinstates better at higher frequencies.
What is pitch?
The property of auditory sensation in terms of which sounds may be ordered on a. musical scale (low to high). It is most closely related to the physical properties of fundamental frequency.
What is timber?
When two tones have the same loudness, pitch and duration, but sound different, this difference is a difference in timber. Timber is closely related to the harmonic structure of a tone.
What is in the outer ear (gather sound)?
Pinna external auditory meatus and tympanic membrane.
What is in the middle ear (mechanical transformer)?
Ossicles and footplate which is connected to the oval window.
What is in the inner ear?
Semicircular canals, vestibule and cochlea.
How do we capture sounds?
The middle ear cavity is air-filled while the inner ear is fluid filled. The middle ear transfers the force from the tympanic membrane to the oval window through the ossicles.
What is the function of the inner ear?
High-frequency sounds cause greatest vibration near the base of the membrane and low frequencies cause greater vibration near the apex.
The basilar membrane has a frequency to place conversion for pure-tone stimuli.
What was the Corti?
The inner ears receptor organ is the organ of court.
How many hair cells does the corti have?
16000 hair cells arrayed in 4 rows: a single raw of inner hair cells and three of outer hair cells.
When are hair cells stimulated?
When the basilar membrane is driven up and down. Because this motion is accompanied by shearing motion between the tectorial membrane and the organ of Corti. The hair bundles that link the two are deflected. This deflection initiates mechanoelectrical transduction of the stimuli.
What do hair cells turn mechanical energy into?
Neural signal.
How is mechanical energy turned into neural signal?
The déplacement of the stereocilia open Ca++ channels in the cells base, which causes neurotransmitter release to excite afferent axons whose cells bodies are in the spiral (or cochlea ganglion).
What does the basilar membrane act as?
A filter.
What do sounds of different frequencies result in?
Maximal displacement at different points along the membrane.
