Lexical segmentation (LS) is a key decoding process that contributes directly to perceptual processing, which in turn supports the parsing of spoken input into meaningful mental models. LS skills enable listeners to analyze sounds in the speech stream and match them to lexical and syntactic stores in memory, the product of which leaves listeners with a literal interpretation of an utterance. This entry explains processing issues faced by second language listeners with particular reference to bottom-up processing and makes a case for developing LS through contextualized activities . It suggests a number of activities that give learners practice at differentiating between words in a speech stream and recognizing intonational features that can assist segmentation of units of meaning.