Week 10 Flashcards
What are sound waves?
Waves of pressure changes in air caused by vibrations
What is the perceptual correlate:
Frequency
Amplitude
waveform
Pitch: hertz
loudness: decibels
timbre: none
What is the difference between frequency and pitch?
Frequency is the pure tone which is related to the perceptual dimension of pitch
Amplitude:
Loudness
decibles
- Physical characteristic
- Perceptual characteristic
- units of amplitude -
what is the Audibility curve ?
What is the minimum threshold for us to hear it
What is pure tone?
Sound wave in which air pressure changes overtime
What is Fourier analysis?
Showed that waveforms of most periodic sounds have a more complex shape
What are harmonics?
Component frequency of complex waveform
What is timbre ?
Difference in sound quality between two sounds with same pitch and loudness
Illusion of the missing fundamental shows that the Auditory systems
uses patterns of frequency in a sounds harmonics as part of pitch
What is the difference between manner of onset and offset?
Manner of onset (attack) and offset (decay) also affect timbre perception
Anatomy of the ear?
Provides direction and funnelling sound
What are the three parts of the ear and their function?
outer(pinna): outside
middle (auditory) canal Mechanical movement
inner: resorting fluid energy
What are ossicles?
three small bones on the middle ear that transmit sound energy
What is the malleus
Small bone in the inner ear
one of the ossicles
transmits sound to the incus
What is the inches (anvil)
small bone in the inner ear
one of the ossicles
transmits sound from malleus to stapes
what is the difference between the inner and the outer hair cells?
inner hair cells convey almost all the info about sound waves to the brain while the outer receives info from the brain (feed back system
what is the neural representation of frequency and amplitude?
auditory system mechanisms are used to encode frequency in the neural signals sent to the brain.
What is the frequency theory?
- suggests that the neurons firing rate matches the Hz
- works only at low frequencies
What is the place code fro frequency?
-established the physical basis for place code
What is the physiology frequency tuning curves?
auditory nerve fibres can be accounted for by the frequency tuning of the basilar membrane (mechanical factor)
Mapping of type I nerve fibres to position in the organ of corti?
Characteristics frequency of auditory nerve fibres and the position in the organ of corti
strong evidence for place coding
What are the features of the auditory brain structure?
cochlear nucleus: first brain stem
superior olive: early brain stem
interior colliculus: midbrain nucleus
medial geniculate nucleus: thalamus that relays signals to temporal cortex
____ Is the psychological aspect of sound related mainly to the fundamental frequency.
Pitch
The acoustic reflex protects the ear from intense sounds by:
Contraction of the stapedius and tensor tympani muscles
The organ of Corti is a structure on the basilar membrane composed of _______ and dendrites of auditory nerve fibers.
Hair cells
A complex sound consists of:
many sinusoidal components of different frequencies.
The _______ consists of three tiny bones called ossicles.
middle ear
Rate saturation occurs when a nerve fiber is firing as rapidly as possible and
further stimulation cannot increase the firing rate
Some auditory nerves fire in synchrony at a particular point in the period of a sound wave, which is called
phase locking
_______ refers to the idea that multiple neurons can provide a temporal code for frequency if each neuron fires first at a distinct point in the period of a sound wave but does not fire on every period.
The volley principle
The phenomenon of _______ occurs when a second sound, frequently noise, is added to make the detection of another sound more difficult.
masking
Why is white noise the best choice for masking random sounds in an environment?
Since white noise includes energy at all frequencies, it is good at masking random sounds of any frequency.
