2. Phonetics, day 2 Oct 3, 2008

3. Phonetics 1.Experimental a. production b. perception 2. Surveys/Interviews

4. b. perception What kinds of research questions are asked about speech perception? 1.identification and discrimination 2.categorical perception 3.signal manipulation (phonemic restoration, signal lengthening, native vs. non-native speech) 4.sound recognition in/out of context (cocktail party/white noise/McGurk effect)

5. 1. identification and discrimination All experiments in speech perception come down to doing one of two things (typically) 1. identification: hear a word/sound and decide what it is. 2. Discrimination: hear two (or three) sounds and decide whether they are the same or different sounds.

6. identification: Where are the speakers from 1 5 6 4 3 2

7. 1 5 6 4 3 2 1. 12. 23. 54. 65. 2 6. 4 7. 1 8. 3

8. discrimination

9. 2. Categorical Perception We perceive sounds in terms of categories—can only hear between category differences, not within category differences. p p p p p p b b b b b bb b

10. Voice Onset Time Categorical Perception The time interval between the release of a stop consonant and the onset of glottal vibrations in the following vowel. b b b b p p p p 10 ms 20 ms 30 ms 40 ms 50 ms 60ms 70 ms 80ms

11. VOT categorical perception Humans perceive human speech sounds as belonging to one category or another. They do not perceive them as continuous. But they perceive other sounds as continuous TOT: VOT:

12. a. High Amplitude Sucking Infant sucks on pacifier that is linked to a computer Used for subjects from 1-6 months

13. b. Conditioned Head Turn Procedure Children learn that when stimuli changes they can look somewhere and get a “reward”

14. 3. Signal manipulation a. Phonemic Restoration (Warren 1970) It was the *eel that was on the table/axle gap normalrestoration

15. b. Lengthening of Speech Signal Slower: Regular: 3. Signal manipulation

16. 4. Sounds in/out of context out of context cocktail party white noise McGurk effect

17. 4. Sounds in/out of context Guess the following words: Words out of context were identified only 47% of the time

18. b. cocktail party effect Humans can ignore other voices while focusing on a single person’s voice. Two Sentences : Can you hear both sentences?

19. c. White noise We can process words better in context than in isolation even in white noise

20. 5. White Noise We can process words better in context than in isolation Word in isolation : Word in Context:

21. d. McGurk Effect We use visual and auditory cues in order to understand speech Why would we do all these experiments? What kinds of experiments can you think to do with your research and experimental phonetics?

22. Phonetics 1.Experimental a. production b. perception 2. Surveys/Interviews

23. Go to Dialect surveyDialect survey In pairs, look at 3 of the questions that examine pronunciation variations—decide 1.Is this a question that would elicit a good response— why or why not? 2.Are the multiple choice answers written in a way that would elicit a good response—why or why not?