Echolocation Flashcards
What is target discrimination?
50 kHz sound has wavelength of 6.9mm, same size as prey, prey would give echo
What are the adaptions of the bat ear?
Outer ears have extended pinna (auricle) and tragus)
lawrence and simmons showed tragus has major role in ventral localization
what is the cochlea?
fluid filled spiral labryinth that houses many hearing structures including BASILAR MEMBRANE, + ORGAN OF CORTI
what is the function of organ of corti?
trigger release of chemicals that create neural impulse
how do bats prevent deafening themselves?
Stapedius muscle clamps down on ossicles, dampens intensity of sound that the bat hears, whenever bat makes echolocation emission
what do stapes cause the vibration of?
basilar membrane
decribe the three sections of the human ear
- outer ear - collects and directs sound
- middle ear filters + amplifies accoustic energy to inner ear
- inner ear transforms acoustic energy to neural impulses that are processed by the brain
what does the outer ear include?
ear fleap (pinna) which funnels sound into..
outer ear canal
ear drum seperatures outer and middle ear
what does the middle ear contain? in land mammals
air filled space containing three small bones (ossicles) - incus, malleus, stapes
these connect the tympanic membrane + oval window, which is opening to inner ear
what does the inner ear contain?
organs for hearing (cochlea) and balance (vestibular system)
cochlea is fluid-filled spiral labryinth containing basilar membrane + organ or corti
what are the two types of hair cell?
outer and inner
outer only found in mammals
3x many outer hair than inner cells.
95% of ganglion neurons communicate with inner hair cells
what are inner hair cells?
main auditory receptors
what plays a major role in the vertical localisation of objects?
tragus (as discovered by lawrence and simmons 1982)
