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