Introduction Research Methods Fall 2010 Tamás Bőhm.
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Transcript of Introduction Research Methods Fall 2010 Tamás Bőhm.
![Page 1: Introduction Research Methods Fall 2010 Tamás Bőhm.](https://reader036.fdocuments.net/reader036/viewer/2022062314/56649da65503460f94a91e6f/html5/thumbnails/1.jpg)
Introduction
Research Methods
Fall 2010
Tamás Bőhm
![Page 2: Introduction Research Methods Fall 2010 Tamás Bőhm.](https://reader036.fdocuments.net/reader036/viewer/2022062314/56649da65503460f94a91e6f/html5/thumbnails/2.jpg)
What is psychophysics?
• Subdiscipline of experimental psychology• Measuring the relationship between physical
stimuli and their subjective correlates (percepts)• Physical dimensions: light intensity, sound
intensity, sound frequency etc.• Subjective/perceptual dimensions: brightness,
loudness, pitch, etc.• Psychophysics: usually refers to vision• Psychoacoustics: hearing
![Page 3: Introduction Research Methods Fall 2010 Tamás Bőhm.](https://reader036.fdocuments.net/reader036/viewer/2022062314/56649da65503460f94a91e6f/html5/thumbnails/3.jpg)
Why do we need psychophysics?
• Physical dimensions ≠ perceptual dimensions• Light intensity ≠ brightness
http://web.mit.edu/persci/people/adelson/
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Why do we need psychophysics?
• Physical dimensions ≠ perceptual dimensions– If you double the intensity of a tone, you won’t hear it
twice as loud! (only 60% louder)– If you change the frequency of a tone, loudness will
also change (loudness depends both on intensity and on frequency)
• Sound intensity ≠ loudness
![Page 5: Introduction Research Methods Fall 2010 Tamás Bőhm.](https://reader036.fdocuments.net/reader036/viewer/2022062314/56649da65503460f94a91e6f/html5/thumbnails/5.jpg)
Why do we need psychophysics?
• Physical dimensions ≠ perceptual dimensions
![Page 6: Introduction Research Methods Fall 2010 Tamás Bőhm.](https://reader036.fdocuments.net/reader036/viewer/2022062314/56649da65503460f94a91e6f/html5/thumbnails/6.jpg)
Some practical uses
• Absolute threshold of hearing
![Page 7: Introduction Research Methods Fall 2010 Tamás Bőhm.](https://reader036.fdocuments.net/reader036/viewer/2022062314/56649da65503460f94a91e6f/html5/thumbnails/7.jpg)
Some practical uses
• Aging and the absolute threshold of hearing
Wikipedia
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Some practical uses
• Hearing aids: compensating for audibility loss by measuring individual audibility curves
pure-tone audiometry
Fletcher, 1929
![Page 9: Introduction Research Methods Fall 2010 Tamás Bőhm.](https://reader036.fdocuments.net/reader036/viewer/2022062314/56649da65503460f94a91e6f/html5/thumbnails/9.jpg)
Some practical uses
• Mp3 music coding:1:10 compression by applying results from psychoacoustics– Absolute and
differencethresholds
– Properties ofbinaural hearing(joint stereo)
– Masking effects
![Page 10: Introduction Research Methods Fall 2010 Tamás Bőhm.](https://reader036.fdocuments.net/reader036/viewer/2022062314/56649da65503460f94a91e6f/html5/thumbnails/10.jpg)
Some practical uses
• Military camouflage: detectability of patterns (different shapes and colors) from different viewing distances, under different conditions