Purpose: Many children have difficulties understanding speech. At present, there are few assessments that test for subtle impairments in speech perception with normative data from U.K. children. We present a new test that evaluates children's ability to identify target words in background noise by choosing between minimal pair alternatives that differ by a single articulatory phonetic feature. This task: (1) is tailored to testing young children, but also readily applicable to adults; (2) has minimal memory demands; (3) adapts to the child's ability; and (4) does not require reading or verbal output. Method: We tested 155 children and young adults aged from 5 to 25 years on this new test of single word perception. Results: Speech-in-noise abilities in this particular task develop rapidly through childhood until they reach maturity at around 9 years of age. Conclusions: We make this test freely available and provide associated normative data. We hope that it will be useful to researchers and clinicians in the assessment of speech perception abilities in children who are hard of hearing or have developmental language disorder, dyslexia, or auditory processing disorder.