REFERENCES Dunton, J., Bruce, C., Newton, C. (2011).
Investigating the impact of unfamiliar speaker accent on auditory
comprehension in adults with aphasia. International Journal of
Language & Communication Disorders, 46 (1), 63-73. Jesse, A,
& McQueen, J. Positional effects in the lexical retuning of
speech perception. Psychon Bull Rev (2011) 1-8. Print. DOI:
10.3758/s13423-011-0129-2 Kraljic, T, & Samuel, A.G. (2007).
Perceptual adjustments to multiple speakers. Journal of Memory and
Language, 56, 1-15. Kraljic, T & Samuel, A.G. (2005).
Perceptual learning for speech; Is there a return to normal?
Cognitive Psychology, 51, 141-178. Myers, E, & L. Mesite.
(2012). Neural systems underlying lexically-biased perceptual
learning in speech. Paper presented at the Neurobiology of Language
Meeting, San Sebastian, Spain. EXPECTED RESULTS METHODS Screening:
We expect to run ~32 participants in the study (16 persons with
aphasia, 16 unimpaired controls.) Participants will be monolingual
English speakers, between the ages of 18-75, with no known hearing
impairments. 1.Hearing Screening- all participants (experimental
and controls) will go through a standard hearing screening to
ensure they are able to hear the stimuli in the experiment.
2.Western Aphasia Battery Test- only the participants with aphasia
will go through an Aphasia Test to test the language function in
these adults and determine the type of aphasia and level of
severity, so we are able to use that information moving forward and
examining their results. Tasks: 1.Lexical Decision Task-
Participants hear tokens of 50 words (ex. bullying, document,
parakeet) and 50 non- words (ex. klogodar, ryligal, wonimtic) in
random order and are asked to decide if what they hear is a word or
a non-word. 20 of these tokens are considered critical words and
contain an ambiguous sound (50% /s/, 50% /sh/) word medially. In
this training we expect listeners to retune to their talker and
adjust previously held phoneme boundaries to accommodate their
speaker. 1.Phoneme Identification Task-Participants hear a
continuum of tokens in the same voice from training, ranging from
30% /s/, 70% /sh/ to 80% /s/, 20% /sh/. Each token is inserted into
a?i and is played randomly 10 times in the set. Participants are
asked to decide if what they hear sounds more like asi or ashi. We
expect participants to classify more ambiguous tokens based on the
type of training they had (Myers, Mesite, 2012). INTRODUCTION In a
dynamic world where relating to others is an important aspect of
life, being able to speak and understand people is essential for
effective communication. However, it is often the case that we have
variation in our speech signal. Examples of Speech Signal
Variations: Boston accent r dropping ( car cah) Southern accent
vowel breaking (cat cayut) Speaker with a lisp (sing thing)
Speaking rate (people tend to talk faster on the East Coast) With
all of this variation in the speech signal we encounter how is it
that we are able to keep a stable perception of incoming speech in
order to understand our talker? Kraljic & Samuel (2005)
suggested two techniques of how this occurs. Two Theories of
Learning New Talkers: 1. One idea is that a listener holds multiple
representations of every speaker they encounter. 2. The other idea
suggests a change in phonemic boundaries after exposure to an
ambiguous phoneme. Previous studies have shown that listeners who
are exposed to a new talker adjust their speech sound categories to
correspond with the new speaker (Kraljic & Samuel, 2005). While
this is easily observed in a non-disordered population, it is
unknown whether the same process occurs in a disordered population,
like persons with aphasia. What is Aphasia? Aphasia is a loss of
language that occurs usually after a left hemisphere brain damage.
People who have aphasia can show a variety of symptoms and
different rates of recovery depending on the type of aphasia and
the severity. Dunton et. al (2011) conducted an experiment where
participants with aphasia heard familiar and unfamiliar accented
speech and tested sentence comprehension. They found that the
individuals with aphasia were lower in accuracy in both unfamiliar
and familiar accents than the non-disordered group. This difficulty
in retuning in persons with aphasia is examined in the present
study. College of Liberal Arts and Sciences Speech and Language
Processing Differences Between Impaired and Unimpaired Populations
Julia R. Drouin, SURF Award Recipient, Summer 2013,
[email protected]@uconn.edu Dr. Emily Myers, PhD,
Department of Speech, Language, and Hearing Sciences Dr. Rachel
Theodore, PhD, Department of Speech, Language, and Hearing Sciences
/s/ group/sh/ group Critical Word Tokens Era?er Coli?eum Epi?ode
Ambi?ion Flouri?ing Publi?er Speaker 1 Speaker 2 Speaker 3 Speaker
2 Speaker 3 Speech Sound Category before new talker Speech Sound
Category after new talker DISCUSSION Differences between
populations: We expect the unimpaired group to adjust their speech
sound categories to accommodate their speaker. Figure 1 shows what
we typically expect to see in an unimpaired population,:
participants will be more likely to categorize ambiguous sounds
based on the type of training received. Figure 2 shows hypothesized
data in the impaired population; participants in both training
groups will not be more likely to define an ambiguous sound as asi
or ashi just based on training. Differences within population: We
also expect to differences within our population of language
impaired individuals. Persons with aphasia have deficits in
language production and comprehension, however they may show more
difficulty in one area. Fluent Aphasia- This group typically has
more difficulty with comprehension than production: we expect to
see difficulty adapting to a variable speech signal and anticipate
results similar to Figure 2. This would predict that fluent
aphasics might have particular difficult adapting to non-standard
speech or accents. Non-fluent Aphasia- This group has relatively
intact comprehension. If we see results similar to Figure 2
(impaired) this may suggest that persons who experience brain
damage may have permanent effects in speech and language
processing. However, given that this group has good comprehension,
we may see results similar to Figure 1 (unimpaired), suggesting
plasticity in the brain and its aptitude to reorganize in order to
persevere speech and language processing abilities. rehearsal
rehearshal Talker 1Talker 2 Group 1 Female /s/Male /sh/ Group 2
Female /sh/Male /s/ rehear?al 30% /s/40% /s/50% /s/60% /s/70%
/s/80% /s/ ashi asi Figure 1 Figure 2