celest fireside chat heather ames july 12, 2007 t oday ’ s heterogeneous classroom students from...

CELEST fireside chatCELEST fireside chatHeather AmesHeather AmesJuly 12, 2007July 12, 2007

TODAY’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?How do the teachers understand the students?

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

WAVES: KEY INGREDIENT FOR SOUNDS

300 Hz wave

500 Hz wave

300 Hz + 500 HzComplex wave

COMPLEX WAVES IN MUSICAL INSTRUMENTS

VOWEL SOUNDS ARE ALSO COMPLEX WAVES

SOURCE-FILTER THEORY

Source: vocal chordsFilter: vocal cavity

Spoken Vowel

DIFFERENT VOWEL SOUNDS

VOWEL CHART

DIFFERENCE BETWEEN MEN AND WOMEN

DIFFERENCES IN F1 AND F2 SPACE

BOTTOM LINE: BRAIN NEEDS INVARIANCE FOR

UNDERSTANDING

HOW DOES THE EAR DISTINGUISH VOWELS?

MY 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?

APPLICATION 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

USEFULNESS IN THE CLASSROOM

Subject Matter Waves Logarithmic scale

and operations Filters Frequency/time

transformations Linguistics English

Communication Understand speech

differences More learning