Delays in auditory development constrain language development

Susan Nittrouer – snittrouer@ufl.edu

Speech, Language, and Hearing Sciences, University of Florida, Gainesville, FL, 32610, United States

Popular version of 2pPP2 – Poverty, prematurity, and the role of auditory functions in language acquisition.
Presented at the 189th ASA Meeting
Read the abstract at https://eppro02.ativ.me//web/index.php?page=Session&project=ASAASJ25&id=3981391

–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–

Language is a uniquely human capacity. Members of other species communicate, but those communications are neither as complex nor as interactional as human language. In spite of its greater complexity, however, human language evolved within the constraints of the mammalian auditory system, a system shared by all mammals. For individual children, spoken language must develop within the constraints of their own auditory systems. But even though the great majority of children can hear sounds at birth, there is a tremendous amount of development in the auditory system that takes place after birth, extending through puberty. This development happens in the central auditory pathways, which means the ability to perform more complex functions on acoustic signals does not reach maturity until near puberty. Thus, a reasonable proposal is that any condition that delays the development of the child’s auditory system can disrupt language development, especially for aspects of language most dependent upon having sophisticated auditory functions. This proposal was explored in this study. Furthermore, the idea was explored that two conditions heretofore known to negatively affect language development may exert some of that influence by disturbing the normal timing of auditory development. These conditions are poverty and premature birth.

Developmental scientists have long searched for the roots of the delays in language acquisition exhibited by children living in poverty. That work has focused on language models in the child’s environment, which are fewer in quantity and poorer in quality than what a middle-class child hears. But even though this factor has been found to explain effects of poverty on child language abilities to some extent, those relationships are never found to be very strong. This means that some other factor(s) must also be contributing.

Children born prematurely are known to have delayed language development, and the usual explanation is that the auditory environment in the neonatal intensive care unit is at once too noisy and too void of the human voice, which is available in utero. Again, those explanations might explain some of the deficit, but animal studies show that the simple act of being removed from the womb before full gestation leads to neurodevelopmental challenges. Obviously, those challenges for animals do not include language acquisition, but for human children born too early, language acquisition can be a challenge.

Our primary findings are:

• Relatively strong relationships exist between measures of auditory function and language measures, and these relationships were strongest for the most complex language skills.
• Socioeconomic status and gestational age at birth were related to measures of both auditory and language development.
• Effects on language development of both socioeconomic status and gestational age at birth could be explained by their effects on auditory function, to at least some extent.

These results mean that developmental delays in the biological structures and functions underlying language disorders are happening long before the language problem can be diagnosed. We need to provide intensive interventions right from birth focused not only on discrete language targets, but on the whole child.