Hearing Flashcards
Outer Ear
external –> tympanic membrane (eardrum) – collects sound waves from environment, into the auditory canal, to interact with the tympanic membrane
- Auricle (pinna)
- Earlobe
- External Auditory Canal
- TYMPANIC MEMBRANE: vibrates with longitudinal sound waves
Frequency – Pitch
Amplitude – Intensity
Middle Ear
tympanic membrane –> oval window
OSSICLES: connects tympanic membrane to the oval window to allow vibration to pass into inner ear
MALLEUS –> INCUS –> STAPES
– connected to Eustachian Tube: part of the nasal cavity that equalizes pressure between the middle ear and environment
Inner Ear – Hearing Apparatus
oval window –> auditory nerve
COCHLEA: hearing apparatus
– hair cells perform signal transduction
– vibrations lead to nerve impulses
– divided into 3 fluid filled chambers (perilymph/endolymph/perilymph)
– BASILAR MEMBRANE: can vibrate
– TECTORAL MEMBRANE: immobile
– HAIR CELLS: attached to the BASILAR MEMBRANE,
stereocilia, mechanosensory receptors
PERILYMPH: cushions structures, transmits vibrations from oval window to cochlea
ENDOLYMPH: bathes hair cells, K+ rich, in the membranous labrynth
Inner Ear – Vestibular Structures
SEMICIRCULAR CANALS – sensitive to rotational acceleration (x, y, z axis)
VESTIBULE – sensitive to linear acceleration
– affects balance and orientation in space
– contains hair cells sensitive to movement
both vestibular and auditory input travels to the auditory nerve
Auditory Processing
signal –> auditory nerve –> superior olive –> inferior colliculus –> medial geniculate nucleus –> temporal cortex
Weber’s Law
RATIO —–> dI/I
The just noticeable difference (JNB) is the minimum difference in magnitude between two stimuli required before one can perceive the difference.
– focus on the ratio between the change and the original value rather than the actual difference between frequencies
– higher magnitude of stimuli requires a higher difference
– ratios below this JNB value will not be noticeable, as this is the minimum threshold.
