From the Autobiography (US ed., vol. 1, p. 247):
He [= Sydney Smith] was not quite the only one of my new friends who did not use my trumpet in conversation. Of all people in the world, Malthus was the one whom I heard quite easily without it; — Malthus, whose speech was hopelessly imperfect, from defect in the palate. I dreaded meeting him when invited by a friend of his who made my acquaintance on purpose. He had told this lady that he should be in town on such a day, and entreated her to get an introduction, and call and invite me ; his reason being that whereas his friends had done him all manner of mischief by defending him injudiciously, my tales had represented his views precisely as he could have wished. I could not decline such an invitation as this: but when I considered my own deafness, and his inability to pronounce half the consonants in the alphabet, and his hare-lip which must prevent my offering him my tube, I feared we should make a terrible business of it. I was delightfully wrong. His first sentence, — slow and gentle, with the vowels sonorous, whatever might become of the consonants, — set me at ease completely. I soon found that the vowels are in fact all that I ever hear. His worst letter was l : and when I had no difficulty with his question, — “Would not you like to have a look at the Lakes of Killarney?” I had nothing more to fear. It really gratified him that I heard him better than any body else; and whenever we met at dinner, I somehow found myself beside him, with my best ear next him; and then I heard all he said to every body at table.