Word Learning inWord Learning in Children with Hearing Loss g

Andrea Pittman, PhD CCC-ASArizona State University

Studies funded by grants from NIH-NIDCD

Why study word learning?Why study word learning?

Children with hearing loss typically have reduced vocabularies compared to children with normal hearingwith normal hearing.

UNHS has produced a new population of children with hearing loss More, better, and longer access to the

auditory signal

What we’ve learnedWhat we ve learned…

Children with hearing loss and children with Children with hearing loss and children with language impairment have similar word learning outcomes but for different reasons HL: Quality of the acoustic signal LI: Cognitive factors

Lexical development appears to be delayed ~2 years in children with hearing loss

What we’d like to knowWhat we d like to know…

How a child’s hearing loss (elevated hearing How a child s hearing loss (elevated hearing thresholds) affects word learning

How access to the acoustic signal (amplification) affects word learning( p ) g

Word Learning ParadigmsWord Learning Paradigms

Learning Performance Paradigm Learning Performance Paradigm Performance after a fixed number of

exposures to a new word

Learning Rate Paradigmg g Number of exposures necessary to learn a

new word

Learning Performance

“Rapid Word-Learning in Normal-Hearing and

Learning Performance

p g gHearing-Impaired Children: Effects of Age, Receptive Vocabulary, and High-Frequency Amplification”Amplification Pittman, Lewis, Hoover & Stelmachowicz (2005) E&H

Purpose Characterize word-learning in children with

normal hearing and children with hearing lossloss

Characterize the effects of stimulus bandwidth on word learningbandwidth on word learning

Novel-Word ConstructionNovel Word ConstructionPlaceLabio- Post

er

Plosive

Bilabial dental Dental Alveola Alveola Palatal Velar Glottal

p b t d k g

Man

ne Nasal

Fricative f v T D s z S Zm n N

hC ∆Approximate

f v T D s z S Zr

hC ∆

jLateral

Approximatelw

Novel-Word ConstructionNovel Word Construction

p b t d k g

f v T D s z S Zm n N

hC ∆f v T D s z S Zr

hC ∆

jlw

Novel-Word ConstructionNovel Word Construction

b v Nr l ∆a Ii o I

p kzZ nj u Q i I

td D smw Ii a i u

g fT S h Co I u I

Novel-Word ConstructionNovel Word Construction

bayrill vojing

youzzap zeekin

deewim tathus

thogish hoochiff

Novel-Word ConstructionNovel Word Construction

bayrill vojing

youzzap zeekin

deewim tathus

thogish hoochiff

Story ConstructionStory Construction

Story PresentationStory Presentation

Bandwidth conditions Standard (LPF 4 kHz) Extended (LPF 9 kHz)

Each word was presented 3 times in the 4-minute story.Th t t d t i The story was presented twice.

Word-learning parameters 8 words 8 words 6 presentations each 8 minute period 8 minute period

ParticipantsParticipants 97 Children between 5- and 14-years-old

60 Normal Hearing (mean age: 9yrs, SD: 2yrs) 37 Hearing Loss (mean age: 9yrs, SD: 2yrs)

Estimated receptive vocabulary (PPVT)Estimated receptive vocabulary (PPVT)

Results

200

Results

160

180

200PP

VT)

NHHL

120

140

160

abul

ary

(P

80

100

120

ptiv

e Vo

ca

40

60Rec

ep

5 6 7 8 9 10 11 12 13 14 15

Age (years)

ResultsResults

80

100re

ct)

NHHL

60

ng (%

cor

r

40

rd L

earn

in

0

20

Wor

5 6 7 8 9 10 11 12 13 14 15

Age (years)

ResultsResults

80

100ec

t)StandardExtended

60

80

ng (%

cor

re

20

40

ord

Lear

nin

0NH HI

Wo

Group

ConclusionsConclusions

Given the same number of exposures, Given the same number of exposures, children with normal hearing learned more words than the children with hearing loss.

An extended bandwidth did not significantly improve word learning in either groupgroup.

What really happens?What really happens?

80

100ec

t)StandardExtended

60

80

ng (%

cor

re

20

40

ord

Lear

nin

0NH HI

Wo

Group

What happens over the long term?What happens over the long term?

80

100re

ct)

60

ng (%

cor

r

20

40

ord

Lear

nin

ExtendedNH HL

00 5 10 15 20 25 30 40 50

Wo Extended

Standard

Exposures

Word Learning Rate “Short-term word learning rate in children with

Word Learning Rateg

normal hearing and children with hearing loss in limited and extended high-frequency bandwidths” Pittman (June 2008) JSLHRPittman (June 2008) JSLHR

Purpose To determine the rate of word learning in g

children with normal hearing and children with hearing loss. Rate defined as the number of exposures

necessary to achieve 70% performance To determine the effect of bandwidth on To determine the effect of bandwidth on

learning rate.

Novel-Word ConstructionNovel Word ConstructionPlaceLabio- Post

Plosive

Bilabial dental Dental Alveola Alveola Palatal Velar Glottal

p b t d k g

Man

ner

Nasal

Fricative f v T D s z S Zm n N

hC ∆M

Approximate

f v T D s z S Zr

hC ∆

jLateral

Approximatelw

Novel-Word ConstructionNovel Word ConstructionLabio- PostPlace

Plosive

Bilabial dental Dental Alveola Alveola Palatal Velar Glottal

p b t d k gNasal

Fricative f v T D s z S Zm n N

hC ∆Man

ner

Approximate

f v T D s z S Zr

hC ∆

j

M

Lateral Approximate

lw

Novel-Word ConstructionNovel Word ConstructionLabio- PostPlace

Plosive

Bilabial dental Dental Alveola Alveola Palatal Velar Glottal

p b t d k gNasal

Fricative f v T D s z S Zm n N

hC ∆Man

ner

Approximate

f v T D s z S Zr

hC ∆

j

M

Lateral Approximate

lw

Novel-Word ConstructionNovel Word Construction

dttt dnn

ssf T s z Sm n

hm

ssf T s z S h

ll

Novel-Word Constructiondn

Novel Word ConstructionTs ´A

ltd zA ´ ltd

f

z

S

A ´

sf Sn ´A

nts mA ´

t lh mA ´

Novel-Word ConstructionStandard Extended

Novel Word Construction

Sothnud

Doztul

Fosnush

Stomun

Homtul

MethodMethod

Children 36 with NH 14 with HL 14 with HL 8-10 yrs of age

Bandwidths Standard (4kHz) Extended (9kHz)

Half the children learned the words in the standard bandwidth and half in the extended bandwidth

150 randomized trials (5 words x 30 repetitions)

Learning GameLearning Game

ResultsResults

180200220

StandardExtended

120140160180

Cor

rect

)

(106) (110)

(99) (95)

406080

100

PPVT

(#

02040

NH HL

GROUP

ResultsResults

ResultsResults

ResultsResults

ResultsResults

N l H i

Number of Trials to Learn 5 New Words

Normal Hearing

Hearing Loss

Standard 43 121Standard 43 121

Extended 20* 72

ResultsResults

N l H i

Number of Trials to Learn 1 New Word

Normal Hearing

Hearing Loss

Standard 16 27Standard 16 27

Extended 5* 10

ConclusionsConclusions

Children with hearing loss require more Children with hearing loss require more exposures to learn a new word than children with normal hearing. As much as 5x the exposures.

Minor acoustic properties can impact long-term word learning. Nothing beats a high quality signal.

In the FutureIn the Future…

Simulating hearing loss to determine effects Simulating hearing loss to determine effects of elevated thresholds on word learning.

Learning Rate paradigm will allow us to quickly assess different hearing-aid, signal q y g , gprocessing characteristics.

Thank you