Temporal resolution

The bottom line

Temporal resolution: How good is a listener at following rapid changes in a sound?

Following rapid changes in sound

Averaging over time is one way the auditory system could Òsmooth outÓ the bumpy response of auditory nerve fibers

The time over which you average makes a difference

The temporal window

Hydraulic analogy: How long before the next bucket leaves for the brain?

People can Òadd upÓ sound energy for

Temporal resolution: How short are the ÒsamplesÓ of sound?

Sensitivity-resolution tradeoff

So how well should I be able to discriminate a change in the duration of a sound?

How to measure temporal resolution

Problem in measuring temporal resolution: ÒSpectral splatterÓ

Duration discrimination

Gap detection

Is it temporal resolution or intensity resolution?

Amplitude modulation detection

Slide 23

Modulation depth

2AFC AM Detection

Modulation depth, 20 log m

AM detection as a function of modulation rate

What sort of filter has a response that looks like this?

The TMTF is like a low-pass filter. That means that we canÕt hear

TMTF at different carrier frequencies

Conclusions from TMTF

The auditory system can follow amplitude modulation well up to about

So how can we detect such short changes in a sound and still be able to integrate sound energy over 200-300 ms?

Two theories of temporal resolution-temporal integration discrepancy

Multiple integrators

AN fibers donÕt have different integration times

Multiple looks

Multiple looks theory says

Multiple integrators theory says

A test of the multiple looks theory: Viemeister & Wakefield (1991)

Viemeister & Wakefield (1991)

Viemeister & Wakefield (1991): Results

The results of Viemeister & Wakefield are most consistent with

Conclusions

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