Impaired Auditory Processing in Children from Low-Income Homes

As the achievement gap between children of different socioeconomic levels stubbornly persists, there is increased awareness of how the home environment impacts learning. New research by Nina Kraus and Samira Anderson at Northwestern University’s Auditory Neuroscience Laboratory reveals that these differences are more foundational than previously thought, affecting not only language ability but auditory processing itself.

Much well-deserved attention has been given to the landmark study by Hart and Risley, which showed that children in poor households are exposed to 30 million fewer words than their better-off peers by the age of four. Yet more recent research suggests that the problem begins even earlier.  According to a study at Stanford University, the gap is already present at the age of 18 months, with children of different socioeconomic levels showing a 200-millisecond difference in how long they take to process basic verbal prompts. Why does this matter? Because auditory processing ability can distinguish good from poor readers, and this is among the first of a set of studies that shows how low socioeconomic status impacts this foundational cognitive skill.

Kraus and Anderson’s work indicates that differences in phonological processing may be to blame. In the study, researchers presented children with a 40-millisecond sound sample of the speech syllable ‘da’. Those in the lower socioeconomic group showed weaker response activity of the complex auditory brainstem, and lower consistency in their responses across trials. In other words, children raised in underprivileged circumstances don’t just have trouble learning words – they have trouble distinguishing sounds themselves.

Consider learning English and encountering the word ‘table’ for the first time in a sentence like “the bowl is on the table”. If you’ve easily understood the rest of the sentence, you’ll be able to use the established context to narrow down the unfamiliar word’s meaning. But if your brain struggles to determine whether you heard ‘bowl’ or ‘pole’, chances are the new word won’t register at all. This is how children’s early weaknesses with auditory and phonological processing grow into difficulties with language, reading and overall learning throughout their academic lives.

Why a focus only on vocabulary is missing the point

What are the implications of this research for educational intervention? Growing public awareness of the socioeconomic disparity in verbal exposure has often resulted in a focus on vocabulary-building exercises designed to bridge the lexical gap. While these sorts of interventions may have a positive impact, they begin at a stage in development where low-income children are already lagging far behind.

Furthermore, focusing on the volume of verbal exposure tends to neglect other important differences in the type and quality of verbal interaction between different socioeconomic strata. Children of professional parents are not only exposed to more words, but also more child-directed conversation and encouraging exchanges that prompt them to make new connections and form new concepts. Meanwhile, children in lower-income households where parents are more stressed and preoccupied with meeting basic needs receive much more of their verbal exposure from overheard speech. When child-directed conversation does occur, research shows it is usually of the negative or forbidding variety, aimed at avoiding further engagement.

For similar reasons, existing interventions are not as effective as they could be. As Susan B. Neuman of the Steinhardt School of Culture, Education, and Human Development points out, initiatives encouraging parents to read to their children promote middle-class cultural practices as a universal solution rather than looking at what works best for students from a low-income household. More recent studies have found that compared to reading exercises, low-income families achieved far better results through the use of phonetic games and recorded examples designed to improve the quality of parent-child conversations.

Along with the recommendation by Drs. Kraus and Anderson to include auditory response tests in evaluating disadvantaged children for potential language impairments, the findings suggest that the effectiveness of educational interventions may be drastically increased by including an auditory component. Through neuroscience-designed exercises targeted at improving the phonological and auditory processing of at-risk students, programs like Fast ForWord have been shown to spark a virtuous cycle in the language acquisition and learning process.

Visit the links below for more information regarding the importance of early intervention and the relationship between reading and phonemic awareness.

10 Ways to Help Your School-Age Child Develop a “Reading Brain”
Phonemic Awareness as a Predictor of Reading Success
Language gap between rich and poor children begins in infancy, Stanford psychologists find
Tackling the "Vocabulary Gap" Between Rich and Poor Children

References:

Low Socioeconomic Status Linked to Impaired Auditory Processing