Loneliness comes up to him like a sniffing dog. It circles him insistently. He waves it away, but it refuses to leave him alone. - Yann Martel

As for hearing, the sloth is not so much deaf as uninterested in sound.

Colonialism is a terrible bane for a people upon whom it is imposed, but a blessing for a language. English's drive to exploit the new and the alien, its zeal in robbing words from other languages, its incapacity to feel qualms over the matter, its museum-size overabundance of vocabulary, it shoulder-shrug approach to spelling, its don't-worry-be-happy concern for grammar — the result was a language whose colour and wealth Henry loved.

science can only take you so far and then you have to leap