§ 6. We now come to a few specimens of the non-vocal sound-phantasms - the mere noises or shocks - which are the parallel among auditory hallucinations to the rudimentary visual hallucinations which were considered in the last chapter. But the auditory cases need a far more jealous scrutiny, before we are justified in regarding them as even probably telepathic in origin. Odd noises, especially at night, are very common phenomena; and though the particular cause of them is often hard to detect, the physical conditions of our indoor life are prolific of possible causes. Most of us are in constant proximity to wind that may blow through crevices, and rattle or flap or dislodge loose parts of our windows and walls and chimneys; and to water in pipes or cisterns that may leak, or burst, or may contain bubbling air; and to slates that may fall; and to wooden furniture and floors that may crack and creak. And if any one should say that he has heard a noise which, from its nature or its position, could not be accounted for by any such ascertainable cause, he might be reminded that sounds are the hardest things in the world to localise; and that no one who has not given special attention to the subject can realise how easy it is to mistake the source and character of an auditory impression.1 . . . Still, unaccountable noises are not of such daily and hourly occurrence but that a sufficiently large and well-established group of the coincidences in question might be taken as possible indications of telepathic action, especially as we have the analogy of rudimentary visual hallucinations to point to.

Moreover, there is no doubt that surprising noises and crashes, though often due to undiscovered external causes, are also a form of purely subjective hallucination2 - which make it at least probable, if telepathy be a reality, that they will also be a form of telepathic hallucination.

[Gurney quotes three cases - 289, 290, 291 - but as they all happen to be somewhat remote, and the class is in itself not a strong one, they are omitted here. - Ed].

1 I may mention, as a marked instance of this, a personal experience which I have again and again repeated. The dripping of a small fountain, heard from some yards off, produces on my ears the precise effect of a heavy waggon which is being slowly dragged up a gravelly road at a considerable distance.

2 See the statistics given, p. 325.