Noonan’s lyrical style has been described as being confessional, occasionally bemusing, and incorporating aphorisms and colloquialisms. Thematically, he is known to cover a wide variety of subject matter. The unconventional nature of Noonan's lyrics is regarded as a signature feature of Bell X1's music. Noonan has also said in the past that most Bell X1 songs are lyrically driven during development stage rather than musically driven. Although the group has never categorised themselves as "Irish rock", lyrically Noonan has often woven in elements from everyday Irish life into songs, from the changing economic fortunes of Ireland during the Celtic Tiger era and subsequent recession, to a popular Irish ice-cream known as a Cornetto.