Speech Production “Problems”

Key problems that science must address How is speech coded? How is speech coded? What is the size of the “basic units” of speech production? What is the size of the “basic units” of speech production? Can explanations of speech control account for context sensitivity (coarticulation)? Can explanations of speech control account for context sensitivity (coarticulation)? How do speakers address the “degree of freedom problem”? How do speakers address the “degree of freedom problem”? To what degree is speech dependent upon sensory feedback? To what degree is speech dependent upon sensory feedback?

How is speech coded? Similar questions What dimensions of speech behavior is “coded” by the nervous system? What dimensions of speech behavior is “coded” by the nervous system? What “reference frame” does a speaker use to determine attainment of targets/goals? What “reference frame” does a speaker use to determine attainment of targets/goals? In what physical domain are speech events planned? In what physical domain are speech events planned?

Some possibilities Auditory perceptual level Auditory perceptual level Acoustic level Acoustic level Articulatory level Articulatory level Aerodynamic level Aerodynamic level

From Browman & Goldstein (1989) Articulatory Targets

From Browman & Goldstein (1989)

From Guenther (1995) Acoustic Targets

Aerodynamic targets From Warren et al. (1989)

What is the size of the “basic units” of speech production? Can explanations of speech control account for context sensitivity (coarticulation)?

What are the basic units of speech production? Key point: Speech is hierarchically and serially organized Key point: Speech is hierarchically and serially organizedPossibilities Phrases Phrases Words Words Syllables Syllables Sounds/phonemes Sounds/phonemes Distinctive features Distinctive features Articulatory movements Articulatory movements Individual movements Individual movements Coordinative structures Coordinative structures

Speech Dynamics The Main Idea: At an abstract linguistic level, phonetic segments (e.g., [b], [p], [r], [k], [i], [A], [u], etc.) are discrete, independent, interchangeable “snap-together” parts – like beads on a string. The [Q] bead is snapped out, an [I] bead is snapped in, changing [kQt] into [kIt]. The [t] bead is snapped out, an [n] bead is snapped in, changing [kIt] into [kIn]. The [I] bead is snapped out, an [Q] bead is snapped in, changing [kIn] into [kQn]. The [k] bead is snapped out, an [m] bead is snapped in, changing [kQn] into [mQn]. The word [kQt] is built by stringing together 3 distinct, discrete “beads” – [k], [Q], and [t]. These are supposed to be beads. From Hillenbrand

The key phrase here is at an abstract linguistic level. At an abstract linguistic level phonemes are discrete, independent, and interchangeable snap-together parts. However, at the actual level of speech production – real movements of real articulators generating real speech sounds – phonetic segments are: not discrete not independent not interchangeable From Hillenbrand

From Tasko and Westbury (2002)

Can explanations of speech control account for context sensitivity (coarticulation)?

Coarticulation Anticipatory (right-to-left) coarticulation Anticipatory (right-to-left) coarticulation A segment’s features are influenced by upcoming segment A segment’s features are influenced by upcoming segment S1 S2

Coarticulation Carryover (left-to-right) coarticulation Carryover (left-to-right) coarticulation A segment’s features are influenced by a previous segment A segment’s features are influenced by a previous segment S1 S2

Selected Examples Nasalization Nasalization deedneen

Lip rounding Frequency Amplitude “Two Sues”“Three Sees”

Lip rounding Frequency Amplitude “Two Shoes” “Three Shes”

[s] from [usu] -> [isi] [s] from [isi] -> [usu] [isi] [usu] From Hillenbrand

How to reconcile the idea of a basic unit of speech production with context sensitivity?

How do speakers address the “degree of freedom problem”?

To what degree is speech dependent upon sensory feedback?