A lot of noise about nothing? Speech-to-noise ratios rather than noise predict language outcomes in preschoolers

It has been proposed that a childhood in a noisy household might lead to poor language skills and slow development of language areas of the brain. Notably, a direct link between noisy households and language development has not been confirmed. Households might have high levels of noise for a range of reasons, including situational (near a large road intersection or airport), family (large families), and cultural (differences in beliefs surrounding noise in the home, including media use). We argue that within the range of safety, noise itself is not problematic to language development if language is made accessible to children. To test this hypothesis, we used LENA (Language Enviromental Analysis) devices to record 3- to 5-year-old children's home environments. All children were living in Spanish-dominant households. Language skills were assessed in Spanish and English. In addition to overall noise levels in the home, we calculated speech-to-noise ratios as an index of access to speech in real-world conditions. There was no relationship between noise in the home and language outcomes. Instead, speech-to-noise ratio explained a significant proportion of variability in language outcomes. The results indicate that enhancing access to language, such as by speaking loudly or getting close to the child, plays a significant role in children's language development outcomes rather than noise per se.