PsychoacousticPsychoacousticssDigging deeper into how we hear

What is Psychoacoustics?What is Psychoacoustics?

It is the SUBJECTIVE HUMAN PERCEPTION of sounds

As we learned, we all hear differently than what might be scientifically measured

Sensory and PerceptionSensory and Perception

Our ears are able to separate certain elements of sound, but not others

This causes compressed sound (Like MP3’s) to sound similar to uncompressed

More on Format More on Format CompressionCompressionSoftware can use the

‘Psychoacoustic Model’ to do audio compression

Understanding how our ears are sometimes unable to discern differences can be an advantage

An MP3 is as much as 1/10 the file size of an uncompressed file

Side effects of our earsSide effects of our ears

INTERMODULATION:Sometimes our perception causes us to hear distortion or other effects that aren’t actually there

Like when tones interfere with one another

Beat FrequencyBeat FrequencyOne example is a ‘beating’ effect

when two TONES are very close to one another

Phantom FundamentalsPhantom FundamentalsRemember: A FUNDAMENTAL is

the lowest pitch in any given sound

If we hear a fundamental that isn’t actually there, it is a ‘Phantom’

Some products take advantage of this

MaskingMaskingWhen one sound is being covered

by another sound, usually louder

For example: A loud bus driving by during a conversation

Temporal MaskingTemporal MaskingWhen our ear’s ‘Acoustic Reflex’

causes us to not near sounds in time

This is usually the sounds directly around a much louder sound in time

Our ears take time to react

Spectral MaskingSpectral MaskingThis is when two sounds are

sharing the same frequency ranges

It causes one to be covered up

This is the biggest concern in mixing

Understanding our Understanding our PerceptionPerceptionRemember that sound is as much

psychological as it is physical!

We all hear in a non-linear way, which changes everyone’s perception

UNIT 2: Auditory UNIT 2: Auditory PerceptionPerceptionNow, we’ll listening to examples

of how our perception causes these side-effects

We’ll hear MASKING and Intermodulation effects

Unit 3: Analyzing SoundUnit 3: Analyzing SoundMore details on Masking

We’ll hear spectral and temporal masking

Unit 4: Non-LinearitiesUnit 4: Non-LinearitiesHow our ears actually generate

distortion

Again, how we don’t hear perfectly like in nature