Psychoacoustics Explained: How Your Brain Hears, Feels, and Shapes Sound

How does your brain turn air vibrations into music, speech, and emotion? This video dives into psychoacoustics—the science of how we perceive sound. Discover how the ear and brain work together, why we hear some sounds but not others, and how modern audio codecs use these principles to compress music without losing quality.

Learn about critical bands, masking, and temporal hearing effects that define what we actually perceive. From the ear’s incredible sensitivity to how we locate sound in space, this video bridges physics, psychology, and sound engineering.

Some of the questions answered in this video:
How can your ear detect a sound gap as short as 1/500 of a second?
Why does your right ear understand words better — and your left ear music?
Can you really hear the difference between 1000 Hz and 998 Hz?
Why does your ear adapt to loud and quiet sounds faster than your eyes adapt to light?
How can a barely audible sound move your eardrum less than a hydrogen atom’s diameter?
Why can a loud sound make another one disappear — even if it’s still there?
What’s the real difference between intensity and loudness?
Why does your brain think a sound is coming from the center when it’s not?
How can two mono signals create a full 3D stereo illusion?
Why does your ear hear midrange frequencies better than bass or treble?
What is a critical band, and how does it decide what sounds you hear or miss?
Why can low frequencies hide high ones — but not the other way around?
How can noise in the right frequency range make a tone vanish completely?
Why can a sound that physically exists still be inaudible?
How can codecs “throw away” audio data and still sound perfect?
Can a sound that happens after another one hide it from your hearing?
What’s the difference between pre-masking and post-masking?
Why do quick sounds sometimes leave a ghost-like echo in digital audio?
How does your brain handle sounds that arrive milliseconds apart?
Can time itself shape what you hear?
How does your brain inspire MP3 and AAC compression?
What is “perceptual entropy,” and why does it decide how much audio can be compressed?
Why do audio codecs spend more bits on some frequencies and fewer on others?
How does a codec know which parts of a song you’ll never notice?
What makes perceptual coding transparent — when loss becomes inaudible?

Perfect for anyone interested in audio perception, music production, or sound design, it reveals the hidden logic behind how we truly hear the world.

0:00 Psychoacoustics
4:18 Physiology of the Human Ear & Critical Bands
5:47 Threshold of Hearing & Masking
8:30 Temporal Masking
10:42 Psychoacoustic Models
13:26 Spreading Function
14:22 Tonality