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Speech Sound Processing in the Brain
Mike KilgardUniversity of Texas at Dallas
Hearing and Language
Hearing is in the BRAIN.
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What was that sound?
OR
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Spectrogram - Example Sounds
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Example Speech Sound - “Bad”8000 Hz
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“Pad” vs. “Bad”8000 Hz
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Cash Gash Sash Rash Lash
I wen t to the bea ch and played in the waves
Your brain while hearing words.
Kraus and colleagues, Science 1996
Brain Responses Da vs. Ga
Normal Learning Impaired
Processing Speech in Noise
Brain Responses to Speech in Noise
How early are differences in brain responses apparent?
Infant brain responses may predict reading 8 years later.
Molfese, Brain &Language, 2000
Can anything be done to improve sound processing?
20±10 vs. 75±20 μV 81±19 vs. 37±20 μV
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Red Group Enriched Blue Enriched
Environmental Enrichment
22 rats total
EnrichedStandard
EnvironmentPhysically
Alters the Brain!
TrainingImproves the Brain
BeforeTraining
After Training
How exactly does the brain process speech sounds?
“Pad” vs. “Bad”8000 Hz
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Sad Dad
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Rad Lad
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Dad?
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Sad?or
But rats can’t hear speech.(or can they?)
Rat can distinguish most consonants!!!
Although rats will never learn to talk or read, this new model is providing new insights intothe early stages of speech processing and
how they might be improved.
Conclusions:
1. Hearing happens in the brain.
2. Fractions of a second matter.
3. The brain doesn’t always do a good job.
5. Our new understanding of neural speech processing may aid development of new therapies.
4. The brain can change.
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Acknowledgements: www.utd.edu/~kilgard
Crystal Engineer Claudia Perez Helen Chen
