system
Given the following post, respond as if you're commenting on Reddit:
human
How does the brain isolate a sound when we focus on it?

Say you were sitting in the car listening to music and someone is talking to you. We can choose to focus on the music the person or say the engine of the car, but how does the brain isolate the sound we want to hear rather than it just all seeming like one big noise?
gpt
The auditory cortex amplifies the signal your consciousness (prefrontal cortex) directs it to focus on, and dampens the rest if it can. If the undesired noise is too loud and overwhelming, you can't filter it out and thus can't concentrate or even hear the noise you want to.