Francis Nolan's interests centre on Phonetic theory. His early research looked at how, and to what extent, the identity of a speaker is encoded in speech - see for instance his book The Phonetic Bases of Speaker Recognition (Cambridge: CUP, 1983 [reissued 2009]), and as a consequence he has been active in the application of Phonetics in forensic science. He led two ESRC-funded projects, DyVis and VoiceSim, which studied aspects of speaker identity. His research interests also include prosody (including speech rhythm and dialect differences in intonation), and the Phonetic variation which occurs in fluent, natural speech. His teaching covers Phonetic theory and description, phonology, practical Phonetic skills, and experimental Phonetics.