Phonological awareness, the ability to manipulate the sounds of language, is key for learning to read. The first step towards phonological competence is identification of syllables and rimes. In a continuous speech stream, syllables and rimes are marked by slow temporal rhythmic modulations, including changes in vowel intensity or amplitude rise time (ART). Prior work suggests that children’s sensitivity to ART predicts reading ability and dyslexia across languages. Yet, little is known about the brain bases of this sensitivity that might be key to both language and reading acquisition. The present study explored the hypothesis that children’s brain response to slow temporal modulations, tested with amplitude rise perception, relates to child reading acquisition. Fifteen young readers (ages 7-12) completed ART and a control intensity discrimination task during fMRI. Behavioral findings validated the link between ART sensitivity, language and literacy abilities in young readers. Neuroimaging findings showed that while bilateral temporal cortexes were active during the ART task, children with better phonological and ART abilities showed reduced brain activation in left temporal lobe. These findings suggest a link between amplitude rise perception and left-lateralized language abilities, and carry implications for better understanding of language, literacy, and reading disability across languages.