What is place coding in the auditory system?
What is place coding in the auditory system?
There are two “classical” ways in which the frequency of a pure tone might be coded within the peripheral auditory system, using either a place or time code. The first potential code, known as the place code, reflects the mechanical filtering that takes place in the cochlea of the inner ear.
How is frequency coded in the cochlea?
The cochlea decomposes sound into bands of frequencies and encodes the temporal waveform in these bands, generating frequency tuning and phase-locking in the auditory nerve (AN). The problem of rate coding at high sound levels may reflect broader spectral filtering in animal models [3].
What is the auditory pathway?
Auditory messages are conveyed to the brain via two types of pathway: the primary auditory pathway which exclusively carries messages from the cochlea, and the non-primary pathway (also called the reticular sensory pathway) which carries all types of sensory messages.
What is auditory tuning?
In auditory system, tuning curve identifies the response of one or some neurons for sound stimuli at different frequencies-intensity combinations. It showed that the neural responses of a specific stimulus with a constant probability varied in different sequences contained of diverse peripheral stimuli.
What is ITD and ILD?
The information embodied in interaural time differences (ITDs) and interaural level differences (ILDs) (a) allows listeners with normal hearing (NH) to locate sound sources on the horizontal plane, and (b) has a significant role in generating high levels of speech recognition in complex listening environments, for …
How does the cochlea perceive sound?
The cochlea is filled with a fluid that moves in response to the vibrations from the oval window. As the fluid moves, 25,000 nerve endings are set into motion. These nerve endings transform the vibrations into electrical impulses that then travel along the eighth cranial nerve (auditory nerve) to the brain.
How is loudness of sound coded for in the cochlea?
Hair cells in the cochlea can code sound intensity via the amount of neurotransmitter they release. Higher sound levels result in more neurotransmitter release and in turn to higher firing rates in the spiral ganglion cells of the auditory nerve.
How do you remember the auditory pathway?
Just remember that the auditory pathway starts with the auditory nerve, goes to its nucleus (cochlear nucleus) and then suddenly turns into slime (visualise this) – SLIMA.
What is the proper pathway for sound?
Sound waves enter the outer ear and travel through a narrow passageway called the ear canal, which leads to the eardrum. The eardrum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear. These bones are called the malleus, incus, and stapes.
How is auditory information coded?
We have seen that in the cochlear nerve, information about sound intensity is coded for in two ways: the firing rates of neurons and the number of neurons active. These two mechanisms of coding signal intensity are found throughout the auditory pathway and are believed to be the neural correlates of perceived loudness.
What is the auditory system?
The auditory system processes how we hear and understand sounds within the environment. It is made up of both peripheral structures (e.g., outer, middle, and inner ear) and brain regions (cochlear nuclei, superior olivary nuclei, lateral lemniscus, inferior colliculus, medial geniculate nuclei, and auditory cortex).
