1. Quizette on Monday get ready Psychoacoustics today

2. What is Psychoacoustics? (see Yost Appendix D) Psyche Psychological, Observer Dependent Acoustics Physics of sound Relationship between the Stimulus and the Perception How sensitive is the sensor?

3. Psychophysics Refresher Limen Difference vs. Absolute Theory of Signal Detection Bias d’ hits & false alarms ROC curves

4. Current issues in Psychacoustics How sensitive is the system in different contexts? Demo: 2 vs. 3 tones Which was more difficult If the spacing is the same why should 3 stimuli be more difficult than 2 stimuli?

5. Loud vs. Quiet Context Non-linear gain control Non-linear: level of gain dependent on stimuli Gain: cochlear amplifier Which is easier: 25, 30, 35, 40, 45 dB SPL set 25, 30, 35, 40, 80 dB SPL set Gain is adjusted What if a 95 dB tone occurs before each stimulus? Gain has top-down & bottom up influences

6. Ear of Stimulation Does a loud sound in the left ear affect the right ear? Why might it? Why might it not? Actual results

7. High vs. Low Frequencies Demo: 900, 950, 1000, 1050 vs. 900, 950, 1000, 2000 Why is aren’t there gain-like adjustments to frequency? Scale size 20 – 20,000 linear scale 0 – 130 dB SPL log scale

8. Upcoming Test Sample Questions online