At what age can children typically start to distinguish units of sound within spoken words?

Children typically start to distinguish units of sound within spoken words around the age of four. At this age, they begin to develop phonemic awareness, which is the understanding that words are made up of individual sounds, or phonemes. This skill is critical for later reading and writing development, as children who can identify and manipulate these sounds are better prepared to understand the alphabetic principle—that letters represent sounds.

By the age of four, children often engage in activities that enhance their phonemic awareness, such as rhyming games or sound matching exercises, which help them to recognize and differentiate sounds within words. While some younger children might begin to show preliminary skills in distinguishing sounds, it is generally at this age that these skills become more pronounced and consistent.