2. CELEST fireside chat Heather Ames July 12, 2007

3. T ODAY ’ S HETEROGENEOUS CLASSROOM Students from different backgrounds: Different accents Different native languages Different uses of language Different pitch Students from different backgrounds: Different accents Different native languages Different uses of language Different pitch How do these students learn to understand each other? How do these students learn to understand each other? How do the teachers understand the students?

4. DIFFERENCES AMONG SPEAKERS ? Pitch between men, women, children Speaking rate Accent Pronunciation in reading Rhythm Stress Pitch between men, women, children Speaking rate Accent Pronunciation in reading Rhythm Stress

5. W AVES : KEY INGREDIENT FOR SOUNDS 300 Hz wave 500 Hz wave 300 Hz + 500 Hz Complex wave

6. C OMPLEX WAVES IN MUSICAL INSTRUMENTS

7. V OWEL SOUNDS ARE ALSO COMPLEX WAVES

8. S OURCE -F ILTER T HEORY Source: vocal chordsFilter: vocal cavity Spoken Vowel

9. D IFFERENT VOWEL SOUNDS

10. V OWEL CHART

11. D IFFERENCE BETWEEN MEN AND WOMEN

12. D IFFERENCES IN F1 AND F2 SPACE

13. B OTTOM LINE : BRAIN NEEDS INVARIANCE FOR UNDERSTANDING

14. H OW DOES THE EAR DISTINGUISH VOWELS ?

15. M Y RESEARCH : HOW DOES THE BRAIN CREATE AN INVARIANT REPRESENTATION OF SPEECH ? Brain organizes frequency on a logarithmic scale Differences in format peaks becomes a ratio log(F1)-log(F2) log(F2/F1) Goal: How does the brain calculate these ratios?

16. A PPLICATION IN TECHNOLOGY Usefulness Voice dictation for doctors, nurses, etc Voice activation for cell phones, GPS, Ipod Telephone based customer service Future Integrate linguistics and meaning with low level engineering solutions More natural speech recognition systems Past Solved engineering problems

17. U SEFULNESS IN THE CLASSROOM Subject Matter  Waves  Logarithmic scale and operations  Filters  Frequency/time transformations  Linguistics  English Communication  Understand speech differences  More learning