Lecture 10 Flashcards
We detect the source of continuous low-pitched sounds by means of what
phase differences
the ears detecting compressed air at the same time? If so, what
the source must be equidistant from the two ears (coming from either right infront, below or above)
The auditory system can identify phase differences of sound waves under 800 Hz, because why
these sound waves have a
half wavelength that is larger than the dimension of the head.
We detect the source of high-pitched sounds how
by analyzing differences in loudness between the ears. (High frequency sounds are significantly dampened as they pass through our heads.)
Most sound waves bounce off folds and ridges of pinna beforewhat
entering ear canal
Most sound waves bounce off folds and ridges of pinna before entering ear canal
• Depending on angle at which sound waves strike these folds and ridges, what can happen
different frequencies will be enhanced or attenuated (i.e. the timbre will change).
Pattern of reflections will change with location of source of sound which will do what to timbre
which will alter timbre of the sound that is perceived
Individual must LEARN to recognize subtle changes in timbre of sounds that originate where
in locations in front of head, behind it, above it, or below it
do we automatically know where sound is in relation to us (from birth?)
no, we have to learn
The fundamental frequency of human speech is what
85-180 Hz for men and 165-255 Hz for women, but the abundance of overtones can give the impression of the fundamental tone
explain how the cochlear implant works
Typically 20-24 electrodes are positioned along the length of the cochlea
Understanding human speech is often best when frequency positions corresponding to 250 Hz to 6500 Hz are stimulated
explain the steps FROM THE EAR TO PRIMARY AUDITORY CORTEX
- The organ of Corti sends auditory information to the brain via the cochlear nerve.
- These axons synapse in the dorsal and ventral cochlear nuclei in the medulla, where copies of the signal are made to be analyzed in parallel ascending paths.
- Axons from the cochlear nuclei synapse in the superior olivary nuclei in the medulla and the inferior colliculi in the midbrain, both of which help localize the source of sounds.
- Axons from the inferior colliculi synapse in the medial geniculate nucleus of the thalamus, which in turn relays the information to the …
- Primary auditory cortex in the tempora llobe
The organ of Corti sends auditory information to the brain via what
the cochlear nerve.
- The organ of Corti sends auditory information to the brain via the cochlear nerve.
- These axons synapse in the dorsal and ventral cochlear nuclei in the medulla, where what happens
where copies of the signal are made to be analyzed in parallel ascending paths.
Axons from the cochlear nuclei synapse in where
the superior olivary nuclei in the medulla and the inferior colliculi in the midbrain, both of which help localize the source of sounds
Axons from the inferior colliculi synapse in where
the medial geniculate nucleus of the thalamus, which in turn relays the information to the …
Axons from the inferior colliculi synapse in the medial geniculate nucleus of the thalamus, which in turn relays the information to the …
Primary auditory cortex in the temporal lobe
Like the basilar membrane, the primary auditory cortex is also organised according to what
frequency
Like the basilar membrane, the primary auditory cortex is also organised according to frequency. Different parts of the auditory cortex respond best to what
to different frequencies
Like the basilar membrane, the primary auditory cortex is also organised according to frequency. Different parts of the auditory cortex respond best to different frequencies.
This organisation where the different frequencies of sound are analyzed in different places of the auditory cortex, is known as what
tonotopic representation
what is tonotopic representation
where the different frequencies of sound are analyzed in different places of the auditory cortex
Primary auditory cortex (core region) is where
in the upper section of the temporal lobe, mostly hidden in the lateral fissure
The belt and parabelt regions refer to what
auditory association cortex.
Like visual information, auditory information is analyzed in what kind of streams
“where” and “what” streams.