Spend enough time working in acute care, and specifically with swallowing disorders, and you get used to hearing the litany of usual "jokes". To that point that, when you hear a new one, it comes quite by surprise and you almost miss the pun.

Phil: Hi, I'm Phil. I'm a speech therapist.
Patient's Mother: Oh, he's here for the swallow test!
Patient's Father: Hey, so if he passes, will he have to take the sparrow test?

It took me a good few seconds to register. I suppose it didn't help that I was staring out the window, at a pigeon roosting on the ledge.

Maybe before long I'll have a good comeback for this.