Flashcards in Week 5 Deck (22):
Human hearing range =
20-20 000 hz
Typical vocal range =
80 - 1100 hz
The fundamental of a sound =
the lowest frequency component of a complex sound
A harmonic =
the integer multiple of a fundamental e.g. 440 fundamental = 880 2nd, 1320 3rd e.t.c.
What helps increase the sound amplitude and detect which direction the sound is coming from?
Pinna (outer ear)
What provides protection, and increases the sound amplitude?
External auditory canal (second part inside the ear) (Still outer ear)
What vibrates in response to sound waves, and moves bones inside the middle ear?
Eardrum (tympanic membrane)(Still outer ear)
Name the ossicles, and their function?
Malleus, Incus, Stapes, Smallest bones in body, transmit vibrations (w some amplification) from the eardrum through to the chochlear via lever actions. Also provide protection from high amplitude sound (muscles attached restrict bone movement). (Middle ear)
Name the 2 constituents of the inner ear?
semicircular canals, and the chochlea.
Describe the structure and function of the chochlea:
contains auditory sensory receptors,stapes from middle ear is connected directly to the oval window - where vibrations are transmitted into the chochlea, is filled with watery substance that transmits vibrations from the middle ear
Name the three canals in the inner ear?
vestibular, tympanic, and chochlea duct, separated by Reissner's membrane, and Basilar membrane, on which auditory receptor cells (hair cells) are located, membranes move in response to the vibrations from the oval window
Explain how neural auditory signals are generated.
When basilar membrane vibrates, the hair cells in chochlear duct are set in motion, converting the vibrations into neural signals.
Postion within cycle
Explain how neural signals are sent via the auditory system
Hair cells move, potassium ions go in pores, neurotransmitters released, neural signals sent down auditory nerves.
List the sites that nerve fibres synapse at on the way to the primary auditory cortex.
1. Chochlear nucleus, superior olivary nucleus, inferior colliculus, medial geniculate nucleus
Where does the auditory signal split and go to each hemisphere?
Splits at chochlear nucleus and is present in both hemis in superior olivary nucleus
List some possible 'things' that are happening on the 'stops' before the sound reaches the auditory cortex.
responses to the onset of sound, changes in sound intensity and frequency
List some tasks which cannot be performed without a cortex
discrimination of sound pattern and duration, localising sounds,
The peak in the ____ indicates the frequency of the sound