SPPA 4030 Speech Science Stephen M. Tasko Ph.D. CCC-SLP Western Michigan University

The Speech Chain (Denes and Pinson, 1993)

What information is embedded within the speech acoustic signal? Phonetic information Affective information Personal information Transmittal information Diagnostic Information

Physical Quantities Basic vs. Derived Scalar vs. Vector Area Volume Displacement Velocity Acceleration Force Pressure Work Power Intensity Resistance – Ohm’s Law (V=IR)

Speech anatomy as “tubes” and “valves” Speech production is achieved through the systematic regulation of air pressures and flows within the lungs and vocal tract.

Branches of science employed to understand speech communication Physics Acoustics Aerodynamics Kinematics Dynamics Biology Anatomy – Gross anatomy – Microscopic anatomy – Molecular biology – Neuroimaging Physiology – Electrophysiology

Source Filter Theory of Speech Production Assumptions in a nutshell What we hear coming out of someone’s mouth is the consequence of – The generation of a sound source – A filtering of that sound source via the vocal tract’s resonant characteristics The source and filter operate in a largely independent manner

Standard Illustration of Source Filter Theory Source (Phonation) Filter (Resonator) Speech (What We Hear) Input Spectrum Frequency Response Curve Output Spectrum

Same Source, Different Filter

Different Source, Same Filters White Noise

Different Source, Same Filters