Critical band

Imagine you are at a party with a lot of different sounds going on. Your ears can hear all of these sounds at the same time, but your brain doesn't process them all at once. Instead, it separates them into different categories based on how similar they are in pitch and frequency.

Each category is called a "critical band." Think of it like a shelf in a toy box where all the toys that look and sound alike are stacked together. The size of the critical band depends on the frequency of the sound. If the sound is low in frequency, the critical band is wider. If the sound is high in frequency, the critical band is narrower.

When your brain separates the sounds into critical bands, it helps you to better understand what you're hearing. For example, if someone is talking to you at the party, your brain will put their voice into its own critical band so that you can understand it better, even if there are other sounds happening at the same time.

Overall, critical bands help your brain to filter out unnecessary noise and focus on the sounds that are most important to you at any given time.