Acts 2:33

He hath poured forth this, which we see, and hear, by the effects, by the noise, as it were of thunder, by our speaking languages, &c. (Witham) --- It does not appear that the holy Spirit was visible to the multitude, whom St. Peter addressed. But they perceived sensible marks of his presence, in the great noise, which had called them together, and the divers tongues spoken by illiterate men, who had never studied. (Haydock)