How the brain processes auditory signals

Many small neurons located in the brain are responsible for the processing of auditory information. By passing through various auditory pathways, the signals are decoded into sounds that we are familiar with and make sense to us.

Once the hair fibres of the cochlea, the snail shell-resembling organ of the inner ear, have sent electrical signals to the auditory nerve, these impulses are transferred to the auditory centre of the brain.

In the auditory brain, several groups of neurons receive the impulses and translate them into a language that our brain understands. This translation occurs in order to cause a conscious perception of the sounds that we receive.

The Auditory Brain

Transformation and processing of sound generally occurs on three levels in the brain: As a reflex, in the auditory cortex and in other brain areas.

Thus, the arrival of the message may first of all trigger a reflex and cause us to jump or turn our head. Thereafter, the processing might also unfold in the auditory cortex, where the sound is consciously perceived.

Other brain areas can allow the perception to become conscious as well and hence recognise the sound by relating it to those that have been memorised in the past. This assessment is followed-up by an appropriate voluntary response.

The processing of decoded sound material starts within the primary auditory pathway. This pathway carries messages from the cochlea to a sensory area of the temporal lobe called the auditory cortex.

In contrast to the primary auditory pathway, non-primary auditory pathways process all sorts of sensory messages. The core function of these pathways is hence to choose the type of sensory message to be treated first. For example, when reading a newspaper while listening to the radio, this system permits the person to focus on the most vital task.

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