chapter ten Flashcards
(22 cards)
stereopsis
using two eyes to infer depth
sound localization
using two ears to infer the location of an object
interaural time difference
The difference in time between the arrival of sound at one year versus the other year. This reliably depends on the azimuth of the sound.
interaural level difference
the difference between the sound amplitude between two ears
Cone of confusion
Any sound source lying on the perimeter of this cone will produce an identical interaural time/level difference
Head movement
We can move our heads around us to help localize sounds
relative intensity
Given two sounds, the loud sound is likely closer to you than the farther sound
how long is the interaural time difference?
300 microseconds
inverse square law
For each doubling distance, the decibel level decreases by 6 dB
Spectral content
Low frequencies carry better than high frequencies, thus fewer higher frequencies likely mean the sound is further away
Hearing loss
30 million Americans have some level of hearing loss. It gets common as you get older
Causes of hearing loss
Blockage of canal
Conductive hearing loss
Sensoneural hearing loss
Blockage of canal
Excessive earwax or other debris blocks canal and attenuates sound waves hitting to panic membrane
Conductive hearing loss
The tympanic membrane and/or ossicles are damaged, preventing the cochlea from receiving sound waves
sensoneural hearing loss
Hearing is lost due to damage to the cochlea or auditory nerve
Source segregation
Processing an auditory scene, consisting of multiple sounds into distinct, auditory events or objects
Timbre
The ability to judge that two complex sounds with the same fundamental frequency as different. This is due to harmonics and high frequencies from different sources.
How does the auditory system localize sounds?
It uses simple, but clever tricks
What type of processing is auditory perception?
Top-down processing
What are the tricks that the auditory system uses to localize sounds?
- By frequency similarity.
- group by timbre
- group by onset time
group by timbre
When we hear multiple sounds
sources, we can try to isolate
them by their timbre
group by onset time
We can also group objects by the order that they ”appear” in the auditory stream. separation has to be at least 30ms. musicians accompany this by having different instruments play at different moments
