Brain and Language 88 (2004) 21–25
Eﬀect of intensive training on auditory processing and reading skills
John A. Agnew, Courtney Dorn, and Guinevere F. Eden*
Center for the Study of Learning, Georgetown University Medical Center, USA
Accepted 27 May 2003
This study assessed the ability of seven children to accurately judge relative durations of auditory and visual stimuli before and
after participation in a language remediation program. The goal of the intervention program is to improve the childrenÕs ability to
detect and identify rapidly changing auditory stimuli, and thereby improve their language-related skills. Children showed improved
accuracy on a test of auditory duration judgement following the intervention without analogous improvements in the visual domain,
supporting the assertion that intensive training with modiﬁed speech improves auditory temporal discrimination. However, these
improvements did not generalize to reading skills, as assessed by standard measures of phonological awareness and non-word
Ó 2003 Elsevier Inc. All rights reserved.
Keywords: Language; Speciﬁc language impairment; Dyslexia; Reading; Temporal processing; Remediation
der Lely & Christian, 2000) and others that the deﬁcit is
speciﬁc to grammar (Bishop, 2000; Sahlen, Reuterski-
It has been proposed that training with acoustically
old-Wagner, Nettelbladt, & Radeborg, 1999). The role
modiﬁed speech can improve the auditory language
of audition has also been examined in developmental
skills of individuals with speciﬁc language impairment
dyslexia, a reading disorder that aﬀects 5–10% of the
(SLI) and dyslexia (Habib et al., 1999; Tallal, Merze-
population. Individuals with dyslexia fail to achieve
nich, Miller, & Jenkins, 1998; Tallal et al., 1996). SLI is
normal reading skills despite adequate intelligence, ed-
generally characterized as a diﬃculty with age-appro-
ucational opportunities, and socioeconomic status
priate use of expressive and receptive language without
(Shaywitz, Shaywitz, Fletcher, & Escobar, 1990). Sev-
other cognitive impairments and is thought to aﬀect 3–
eral studies have reported that children with SLI and
10% of children (Bishop, 1994). In addition to their
dyslexia cannot diﬀerentiate between rapidly changing
linguistic diﬃculties, individuals with SLI are often
consonant–vowel (CV) syllables when presented at
found to also have deﬁcits in non-linguistic domains
normal speed (Tallal, Miller, & Fitch, 1993; Tallal et al.,
such as planning complex oral-motor patterns, working
1996). It has been suggested that this ability is important
memory, sound perception, and visual imagery (Joanisse
for language acquisition and the development of pho-
& Seidenberg, 1998).
nological awareness and reading skills (Talcott et al.,
According to some research, approximately 50% of
2000; Tallal et al., 1993) and that deﬁcits in this domain
children with speciﬁc language impairment have reading
may result in impaired language facility including
problems when tested in second and fourth grades
(Catts, Fey, Tomblin, & Zhang, 2002). Although the
The intervention program studied here attempts to
cause of SLI remains controversial, some suggest that it
address such deﬁcits by modifying normal speech in
is due to a deﬁcit processing input in the auditory do-
such a way that the most rapidly changing components
main (Skipp, Windfuhr, & Conti-Ramsden, 2002; van
are extended in time by 50% and ampliﬁed by up to
20 dB (Nagarajan et al., 1998; Tallal et al., 1996). These
increases in duration and volume are designed to en-
Corresponding author. Fax: 1-202-687-6914.
E-mail address: email@example.com (G.F. Eden).
hance the salience of the fastest-changing components of
0093-934X/$ - see front matter Ó 2003 Elsevier Inc. All rights reserved.
J.A. Agnew et al. / Brain and Language 88 (2004) 21–25
speech, facilitating their perception by the listener. This
These results suggest that training with modiﬁed
modiﬁed speech is embedded in computer games that
speech improves receptive language and phonological
are presented to children over the course of the training,
skills in children. However, it has not yet been deter-
which usually lasts about 6 weeks. During training, the
mined whether these improvements in oral language are
speed and volume of the CV syllables are gradually re-
due to an increased ability to accurately perceive and
turned to the levels found in normal speech. Hence, at
process auditory stimuli or if they might be better ex-
the end of training, the speech presented by the program
plained by other mechanisms. For example, the intense
is almost the same as normal speech in terms of volume
monitoring of stimuli on the computer screen might lead
and rate of presentation (Tallal et al., 1996).
children to attend more eﬀectively. A related question,
This program has been studied in a laboratory set-
which pertains to all intervention programs, is whether
ting, exposing children with SLI to the acoustically
the improvements are speciﬁc to the particular tasks that
modiﬁed speech for three hours a day, ﬁve days a week
comprise the program or if the observed gains generalize
for four weeks (Merzenich et al., 1996; Tallal et al.,
to other skills, such as reading.
1996). Following training, the children improved by
This study addressed two questions: ﬁrst, can the
approximately 2 years on standardized measures of
original ﬁndings from a laboratory setting reported by
speech discrimination and language processing, im-
Tallal et al. (1996) be reproduced in a clinical setting?
provements that endured at least 6 weeks after training
Speciﬁcally, are there measurable gains in auditory
(Tallal et al., 1996). In a second experiment, conducted
processing that are not directly trained by the inter-
by the same investigators, children with SLI were re-
vention program? Second, does training with acousti-
cruited and divided into two groups. One group received
cally modiﬁed speech result in reading gains? To address
training with the modiﬁed speech while the other re-
the ﬁrst question, subjects were recruited from and tes-
ceived equal training using unmodiﬁed speech. After 4
ted at a local clinic. Although this allowed for less
weeks of training, both groups showed improvements on
stringent inclusion/exclusion criteria for the subject
measures of receptive language skills, but the group that
population and administration of the intervention pro-
received training with the modiﬁed speech showed sig-
gram, it more accurately represented the environment in
niﬁcantly greater improvements (Merzenich et al., 1996;
which the intervention program was delivered to these
Tallal et al., 1996).
children. To address the question of the speciﬁcity of
Reading skills, including non-word decoding, and
training, a task measuring the ability of participants to
phonological awareness were not assessed by these
accurately judge relative duration in both the auditory
studies (Merzenich et al., 1996; Tallal et al., 1996). Al-
and the visual domain was administered to children
though additional investigations have been performed
participating in the program. Previous studies have used
outside the laboratory in clinics and classrooms, en-
measures of oral language skill, but not reading
rolling individuals diagnosed with SLI, attention deﬁcit
achievement, as outcome measures (Tallal et al., 1996).
disorder, autism, and dyslexia (Tallal, 2000; Tallal et al.,
Further, these language outcome measures and the ac-
1998), reading gains have not been reported to date.
tual intervention program share many common features,
Language skills, however, were assessed by professionals
so that improvement in these tasks is not unexpected. In
in the clinics and the authors reported that signiﬁcant
the present study, the tasks were designed to be an in-
improvements were observed on standardized measures
dependent measure of auditory duration judgement not
of speech and language, regardless of which measures
speciﬁcally trained. The visual modality was chosen as a
were used by the various clinics. Results from these
control condition in which improved performance is
studies have led the authors to conclude that the Fast
expected if the intervention induces general changes in
For Word program is eﬀective for individuals with a
attention (or other) processes and not in auditory pro-
range of language and communication disorders (Tallal
cesses per se. It was hypothesized that subjects would
et al., 1998; Tallal, 2000).
improve on the auditory duration judgment task but not
Further support for acoustically modiﬁed speech as
on the visual task. It was further hypothesized that in-
an eﬀective intervention comes from an investigation in
tervention would improve skills associated with non-
12 children diagnosed with pure phonological dyslexia
word decoding and phonemic awareness, skills related
(Habib et al., 1999). Experimenters subdivided their
to reading acquisition.
population into an experimental group that received
intervention using the modiﬁed speech and a control
population that received training using normal speech.
Their results indicated that after 5 weeks of training, the
experimental group showed signiﬁcantly greater im-
provements on a phonological task in which they had to
identify the non-rhyming word in a set of four words
All subjects participated in the intervention program
than did the control group (Habib et al., 1999).
J.A. Agnew et al. / Brain and Language 88 (2004) 21–25
Berkeley, CA) until they had achieved accuracy scores
Seven subjects (four male, three female) were re-
of 90% correct on ﬁve of the seven tasks that comprise
cruited and had a mean age of 8.07 years (SD ¼ 1:19).
the program. This criterion is deﬁned as completion of
They were tested on the duration judgement tasks at the
the training and achievement of good temporal pro-
beginning and completion of training. During these two
cessing skills. Children participated in the intervention
testing sessions, subjects were also given two measures
for 100 min a day, ﬁve days a week for approximately
of phonological awareness, the Word Attack subtest
(Form A and B) of the Woodcock Diagnostic Reading
Battery (Woodcock, 1997), which tests non-word read-
2.2. Judgement of duration
ing, and the Phoneme Deletion subtest of the Phono-
logical Awareness Test (Robertson & Salter, 1997). A
Each task (auditory and visual) was broken into four
second form of this test was generated for post-inter-
blocks, each of which lasted approximately 4 min and
vention testing by matching the words on the original
the entire experiment, including both components, las-
form for word length and frequency using the MRC
ted 30–40 min. Trials were presented via SuperLab v. 1.0
Psycholinguistic Database (Culling, 1990). The average
(Cedrus Corporation, San Pedro, CA) on a Macintosh
standard score on the Word Attack subtest before
Powerbook 1400c (Apple Computer, Cupertino, CA).
training was 108 (SD ¼ 29) and it was 85 (SD ¼ 21) on
Data on duration judgment accuracy and response time
the Phoneme Deletion subtest.
Practical considerations led to the selection of the
The auditory task contained a ﬁxation point that was
two tests of reading-related skills: both have been nor-
present at the center of the screen for the entire experi-
malized so that data from this study could be compared
ment. For each trial, an 800 ms tone was followed by an
with a large reference population. Second, they could be
inter-stimulus interval of 500 ms and then a tone of
performed quickly using pencil and paper and within a
variable duration. The duration of this tone diﬀered
time frame acceptable to the private clinic setting.
from the ﬁrst tone by between 10 and 3200 ms. The
Third, the phoneme deletion task assesses sublexical
order of presentation was pseudorandom and a staircase
processing and hence provides a measure of phonemic
procedure was not used. Following the second tone,
awareness. Phonemic awareness serves as a strong pre-
subjects responded by pressing one of two marked keys
dictor of reading ability (Wagner & Torgesen, 1987)
to indicate whether the second tone was longer or
and has not been assessed in previous studies investi-
shorter than the ﬁrst. After responding, subjects auto-
gating the outcomes of acoustically modiﬁed speech
matically advanced to the next trial; no feedback was
provided. After every seventh trial, a picture of an ani-
mal appeared on the screen for 2 s to make the task more
stimulating. All tones were presented at 1000 Hz via
headphones at a level of 78 dB.
In the visual form of the experiment, the timing was
Data collected from the duration judgment study
the same but the auditory tone was replaced with a
were analyzed using a 2 Â 2 repeated-measures ANOVA
yellow smiley face subtending 2° of visual angle and
(Modality Â Day) to examine both accuracy and reac-
placed at the center of a white background on the
tion time. For accuracy, there was a signiﬁcant main
computer screen. As with the auditory experiment,
eﬀect of day (F ð1; 12Þ ¼ 6:36; p < :05), indicating that
subjects had to judge whether the second stimulus was a
subjects performed more accurately after training than
longer or shorter duration than the ﬁrst stimulus. Visual
before training. There was also a signiﬁcant interaction
stimuli were presented on a computer monitor 0.4 m
of day by modality (F ð1; 12Þ ¼ 6:36; p < :05). Post-hoc
from the subject.
paired t tests indicated that subjects were signiﬁcantly
more accurate on the auditory task after training than
tð6Þ ¼ 3:27; p < :05) but not on the visual task (60%
Subjects were recruited from a group of children who,
correct vs. 60% correct; tð6Þ ¼ 0, n.s.), as shown in Fig. 1.
for a fee, were receiving the modiﬁed speech intervention
There were no signiﬁcant eﬀects for the reaction time
program at a private suburban clinic. The selected
data. After training, the average standard score on the
population is therefore representative of the sample
Word Attack task was 110 (SD ¼ 27) and 90 (SD ¼ 20)
typically enrolled for intervention in terms of back-
on the Phoneme Deletion subtest. This represented no
ground, age, and language ability. The children attended
signiﬁcant improvement from the pretest values on ei-
the clinic over the summer and their participation re-
ther the Word Attack (tð6Þ ¼ 0:53, n.s.) or Phoneme
sulted from one or several factors, such as clinicianÕs
Deletion (tð6Þ ¼ 1:14, n.s.) tasks. Hence, gains in the
recommendation, parental concern or poor academic
ability to perceive auditory durations did not generalize
to changes in skills related to reading.
J.A. Agnew et al. / Brain and Language 88 (2004) 21–25
reading skills, as assessed by tests of phonemic awareness
and non-word reading. Only one child showed a minor
improvement on a standardized non-word decoding task
while the rest remained unchanged. This apparent con-
tradiction of previous ﬁndings may be resolved in future
studies, which could recruit more subjects, obtain more
extensive behavioral measures, including measures of
reading comprehension and receptive and expressive
language and obtain long-term, follow-up data.
The results of the current study indicate that some
children who undergo training with acoustically modi-
ﬁed speech do show improvement on the judgement of
Fig. 1. Group accuracy data for auditory and visual modalities. There
auditory durations. However, these changes are not
is a signiﬁcant diﬀerence between pre- and post-training for the audi-
accompanied by improvements on standardized mea-
tory modality (p < :05) but not for the visual modality.
sures of reading, illustrating the need for further re-
search to establish the relationship between reading and
auditory temporal processing. Recently, some re-
searchers have questioned the assertion that the lin-
In these studies, the eﬀect of an intervention program
guistic diﬃculties observed in children with SLI and
using acoustically modiﬁed speech on the judgement of
dyslexia result from a temporal processing deﬁcit in the
non-linguistic sensory information in the auditory and
auditory system. Instead, these authors argue that the
visual modalities was measured. If performance had
ability to detect the changes in pitch that characterize
improved on both the auditory and the visual duration
the formant transitions of phonemes is not a temporal
judgment tasks following training, it could be concluded
processing task at all, but a sensory processing task that
that the training aﬀected a general system (such as at-
must be accomplished rapidly. Instead of an ‘‘auditory
tention). Our results from a small group of children
temporal processing deﬁcit,’’ they suggest that there is a
suggest that improvements were limited to the auditory
speciﬁc deﬁcit in the phonological representations in
system, tentatively supporting the proposition that the
individuals with SLI and dyslexia (Mody, Studdert-
program improves the ability to perform ﬁne discrimi-
Kennedy, & Brady, 1997: Studdert-Kennedy, Mody, &
nation only in the auditory modality. Previous studies of
Brady, 2000) and a weakness in the ability to identify
training using modiﬁed speech have reported improve-
similar phonemes (Adlard & Hazan, 1998). Our results
ments on phonological tasks with groups of only six
in this study support this assertion, as improvements on
subjects (Habib et al., 1999), supporting the view that
a task in which subjects improved in their ability to
the eﬀect detected in the current study of seven subjects
accurately perceive auditory durations did not general-
is genuine and not an artifact of small sample size.
ize to improvements on reading skills.
A second hypothesis of this study was to explore
To our knowledge, the present study is the ﬁrst in-
possible relationships between auditory temporal pro-
dependent demonstration of the eﬀects of training with
cessing skills and reading in children undergoing inter-
modiﬁed speech on sensory perception conducted in a
vention training in a private clinic setting. Although the
clinical setting. More studies are necessary to charac-
initial studies of the Fast ForWord program by Tallal
terize the exact relationship between performance on
et al. (1996) and Merzenich et al. (1996) did not assess the
auditory temporal processing, reading skills and reading
eﬀect of training on reading skills, their subsequent work
suggests that the program can assist individuals with
developmental dyslexia (Tallal, 2000; Tallal et al., 1998).
Studies by Habib et al. (1999) identiﬁed improvements in
phonological awareness following training with acous-
tically modiﬁed speech. Another study identiﬁed a sig-
We wish to acknowledge the staﬀ of the National
niﬁcant positive correlation between reading skills and
Speech and Language Therapy Center, especially Sabra
sensitivity to changing auditory and visual stimuli (Tal-
Gelford and Betty Soret.
cott et al., 2000), suggesting that improvements in au-
ditory duration judgement might be correlated with
improvements in readings skills. The results of the
present study did not support this hypothesis. Although
subjects successfully completed the intervention program
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- Effect of intensive training on auditory processing and reading skills
- Judgement of duration