Loudness and Pitch

Loudness

Subjective with intensity

Increases with:

• Sound Pressure Level

• Frequency

• Duration

Temporal Integration

Sounds <200 ms are perceived as quieter

Equal Loudness Curves

• Shows how loudness perception varies with frequency

• Steeper curves at low SPLs, flatter curves at high SPLs

• Ears most sensitive around 2-5 kHz (speech region)

Phon

Matches perceived loudness to 1 kHz tone in dB SPL; ordinal (ranks loudness)

Sone

Ratio scale

2 sones is twice as loud as one

4 sones is twice as loud as two

Context Effect

Perception is affected by:

• Adaption to sound levels

• Cognitive factors (attention, memory, expectation)

• Previous exposure to sounds or environments

Pitch

Subjective sense of frequency

Affected by movement and asymmetries

Mel Scale

Nonlinear perceptual pitch scale; greater sensitivities to pitch changes at low frequencies

Temporal Coding

Tracks repeating waveform patterns

Place Coding

Maps frequency to cochlear location