Billie Eilish has opened up about her “frustration” at the lack of understanding surrounding Tourette’s syndrome, having been diagnosed with the condition aged 11 . The “Birds of a Feather” singer spoke about her experience with the neurological condition , which is characterised by unintentional movements and vocalisations known as tics, during an appearance on Amy Poehler’s Good Hang podcast. The 24-year-old explained that for her, those vocal tics predominantly came out in the form of noises that she could keep fairly quiet, “luckily for me and for everyone else”. Eilish was diagnosed with the condition aged 11 (Getty) Eilish then explained: “I go through phases of words becoming tics, but there’s this thing called suppressing, if you’ve ever heard of it.…