A Processing-based Account of Acoustic Reduction

(or: Reduction Comes From Facilitation of Levels of Language Production)

Jason M. Kahn & Jennifer E. ArnoldUNC-CH

ETAP Montreal!

Thanks

• Molly Bergeson, Andrés Buxó, Kellen Carpenter, Sam Handel, Leighanne Mcgill, Kayla Finch, Alyssa Ventimiglia, Liz Wagner for help with experiments

• The PLUG group at UNC for valuable critical commentary, as well as Scott Fraundorf, Florian Jaeger, Tuan Lam, and Joseph Tyler

Introduction

Body

Conclusion

Teacher: “Today we’re learning about the structure of a paper. What do these elements do?”

Zzz…

Students (in unison!): “The introduction lays out the problem, the body presents evidence, and the conclusion gives the take home message.”

Scenario 1

Introduction

Body

Conclusion

Teacher: “Today we’re talking about the introduction, the body, and the conclusion – what do they do?”

Zzz…

Students (in unison!): “The introduction lays out the problem, the body presents evidence, and the conclusion gives the take home message.”

Scenario 2

Repeated Mentions Get Reduced (e.g. Bard et al., 2000; Fowler & Housum, 1987)

Teacher:“Structure… elements…”

Linguistically Given Discourse Status

+givenness +predictability

Teacher:“introduction … body …

conclusion …”

Students:“introduction … body …

conclusion…”

Linguistically New Discourse Status

-givenness -predictability

Students:“introduction … body …

conclusion…”

Arnold (1998)

General Questions

• What mechanism drives speakers to reduce words in certain contexts?– Facilitation of multiple levels of processing (either the

representations themselves or the algorithms that operate on them)

• Does reduction occur with the listener in mind, or with respect to only the speaker’s internal state?– Probably a mix of both, but I’ll provide evidence of the

latter

Two Classes of Explanation

Discourse status– Discourse Status – defined as

the relative accessibility or givenness of a referent (Ariel, 1990; Gundel et al., 1993)

– Typically conceived as shared information (Clark & Haviland, 1977)

Speakers reduce when they can rely on common discourse status

Facilitated Processing– Hearing or reading words

activates representations associated with language processing (e.g. lemmas, phonemes)

Speakers reduce for themselves

ORSpeakers reduce for their

listener

Joint Discourse Status

CONCEPTUALIZATION STAGE

DISCOURSE STATUS(given vs. new)

(what speaker and listener both know)

FORMULATION STAGE

ARTICULATION STAGE

Adapted from Levelt (1989), Schmitt, Meyer & Levelt (1999), and van der Meulen, Meyer, & Levelt (2001)

CONCEPTUALIZATION STAGE

DISCOURSE STATUS(given vs. new)

(what speaker and listener both know)

“introduction”

Fowler & Housum, 1987; Prince 1992

Joint Discourse Status

Introduction

Body

Conclusion

Reduction!

CONCEPTUALIZATION STAGE

FORMULATION STAGE

ARTICULATION STAGE

Facilitation-based

Adapted from Levelt, 1989; c.f. Balota, Boland & Shields, 1989; Bard et al., 2000; Bell et al., 2009

CONCEPTUALIZATION STAGE

FORMULATION STAGE

“introduction”

Introduction

Body

Conclusion

Reduction!More Reduction!

Facilitation-based

Linguistic vs. Non-linguistic Givenness

“The accordion…”

Bard & Anderson, 1990; Clark & Marshall, 1981; Prince, 1992

CONCEPTUALIZATION STAGE

FORMULATION STAGE

CONCEPTUALIZATION STAGE

DISCOURSE STATUS(given vs. new)

(what speaker and listener both know)

FORMULATION STAGE

Joint Discourse Facilitation-based

Instruction-giving Task

Speaker

Approximately 12 feet

Listener

Experimental Paradigm

Speaker: “The accordion rotates right”

Speaker: “The toothbrush shrinks”

Speaker: “The belt expands”

Experiment 1: Priming Information

“The toothbrush;The belt;

The accordion”

Control Non-linguistic Linguistic

Joint Discourse Status predicts….

Facilitation-based predicts…

Predictions

Reduced Duration of the Object Word

Linguistic

Non-linguistic

Control

360 370 380 390 400 410 420

Linguistic < Non-linguistic < Control

*

*

Facilitation-based Account Explains the Results Naturally

Non-linguistic information led to reduction

Linguistic information led to more reduction

This task gave the priming information to both the speaker and the listener simultaneously…

Will Speakers Reduce For Their Listener?

• Discourse status says yes – but only when they share information

• Facilitate-for-the-listener says yes – whenever the listener has relevant information

• Facilitate-for-the-speaker says no – speakers will reduce whenever they have information

Instruction-giving Task

Speaker

Listener

1) Blocked trials

2) Icon at the top of the screen

3) Headphones

v v

v v

Both

Speaker

Listener

None

405 410 415 420 425 430 435 440 445 450 455

Reduced Object Word Duration

(Both, Speaker) < (Listener, None)

*X

X

Facilitation Once Again Provides a Natural Explanation

• Speakers reduced words when, and only when, they had relevant information

• This is contrary to a strong audience design account

• For evidence of listener attention on speaker’s acoustic decisions, see Elise Rosa’s talk tomorrow

• For evidence of listener-driven speaker attention on speaker’s acoustic decisions, see Jennifer Arnold’s talk tomorrow

Facilitation at Multiple Levels

• Experiments 1 and 2 provide support for a facilitation-based account, where facilitated levels lead to reduction

• It could be that facilitation might matter only at early stages of production, or it could be that facilitation at any level creates reduction

• Experiment 3 will try to prime a different level of representation – the articulatory level

c

c

Name these objects aloud

c

Name these objects silently to yourself

Or…

c

Then…

c

c

Or…

Spoken Aloud Cond. Silent Naming Cond.

Congruent Cond. Incongruent Cond.

Spoken Aloud Spoken Internally

Congruent Prime Facilitated articulation Unfacilitated articulationIncongruent Prime Facilitated articulators? Unfacilitated representations

CONCEPTUALIZATION STAGE

FORMULATION STAGE

ARTICULATION STAGE

Spoken Aloud Spoken Internally

Congruent Prime Facilitated articulation Unfacilitated articulationIncongruent Prime Facilitated articulators? Unfacilitated representations

CONCEPTUALIZATION STAGE

FORMULATION STAGE

ARTICULATION STAGE

Congruent Prime/Target

Incongruent Prime/Target

410 420 430 440 450 460 470

Spoken Internally

Spoken Aloud

*

*

*Interaction

Reduced Object Word Duration

Congruent+Aloud < (Congruent, Aloud) < Incongruent + Internal

Facilitation of Articulation Creates Reduction

• Speakers reduced after speaking the target aloud, relative to saying it internally

• Speakers also reduced after simply speaking aloud (even to incongruent targets)

Speaker-internal Facilitation Explains It All

• Speakers reduce more for linguistic than non-linguistic givenness• Speakers reduce when, and only when, they have priming

information• Speakers reduce more after saying the word aloud than saying it

to themselves

• This implies that we don’t need a discourse representation to account for these results

• It also implies that at least some acoustic reduction is entirely speaker-driven

• This speaker-driven reduction is plausibly explained by a multiple-levels-of-facilitation account