NeuroBites Quiz is a series of bite-sized brain lessons for educators, therapists and parents working to improve brain function.
What part of the brain is used to understand spoken language?
a) The brainstem
b) The thalamus
c) The auditory cortex
d) All of the above
The Primary Auditory Pathway includes the brainstem, the thalamus and the auditory cortex, so if you answered “d), All of the above,” you are correct.
Primary Auditory Pathway Details
As is the case with most brain functions, multiple areas of the brain are involved. The brain is a dynamic, self-organizing system both modular and distributed, and the path from sound waves to meaning involves many brain areas – much like a local train making many stops along its travels before arriving at its destination.
Proper sound detection initiates the path of deciphering meaning from spoken language. Sound waves emitted by someone speaking are funneled into the ear by the outer ear, made more intense by the middle ear and transduced into neural signals by the inner ear. Hair cells of the cochlea in the inner ear are sensitive to the pressure fluctuations of the frequency (which is perceived as pitch) and intensity (perceived as loudness) of sound waves. Specialized neurons in the cochlear nucleus send this information to the auditory nerve by varying the timing patterns of their electrical signals. This information is delivered to the auditory cortex within the temporal lobe via the primary auditory pathway.
- The first stop in this pathway is in the brainstem where signals of duration, intensity and frequency are decoded and information from both ears is brought together.
- The second stop is the thalamus – a sort of a relay station where almost all sensory processing trains make a stop.
- Here, information from other sensory systems is processed and integrated. This is one place where visual information, for instance, is integrated with sound signals.
- The thalamus’ job of integrating sensory input is demonstrated in a quick audio illusion known as
the McGurk Effect.
- The third and final stop of the primary auditory pathway is the auditory cortex.
- Much of the signal has been decoded at previous stops, but here the signal is recognized, remembered and a response is initiated.
- Signals are sent via specialized pathways for speech recognition, speaker identification and processing for meaning in other areas of the temporal lobe.