Date of Completion


Embargo Period



Bernard G. Grela, Tammie J. Spaulding

Field of Study

Speech, Language, and Hearing Sciences


Master of Arts

Open Access

Open Access


For infants, acquiring vocabulary for nouns is a dynamic, complex process that involves pairing an auditory token with a visual referent. This process is computationally complex because the acoustic information produced for a verbal production of any given noun varies considerably due to factors including the person who is speaking, speaking rate, and linguistic context. Likewise, visual referents are also variable in characteristics such as size, shape, material, and color. Research suggests that variability in either the auditory or visual domains can facilitate early word learning. However, the role of simultaneous variability in these domains on noun learning remains unexplored. Using a 9-week training study, we examined the effects of auditory and visual variability on word learning and generalization in 12 children ages 16- to 23-months in order to collect pilot data for a larger-scale investigation. All children were taught 12 nouns and were randomly assigned to one of four training conditions: low visual and low auditory variability, low visual and high auditory variability, high visual and low auditory variability, or high visual and high auditory variability. High versus low auditory variability was manipulated by presenting ten talkers versus one talker, respectively. High versus low visual variability was manipulated by presenting variable, dissimilar exemplars versus highly similar exemplars, respectively. The results to date suggest that high levels of variability in the visual domain facilitated learning of trained items but did not influence the ability to generalize that category to novel visual exemplars. Moreover, overall vocabulary development appeared to be facilitated by high variability in the auditory domain. These findings provide promising pilot data for understanding how visual and auditory variability influence word learning not only in the laboratory, but also in the real-world linguistic environment.

Major Advisor

Rachel M. Theodore