“The speech of an angel or of a spirit with a person is heard as sonorously as the speech of one person to another, yet it is not heard by others who stand near, but by the person themselves alone. The reason is, the speech of an angel or of a spirit flows at first into the person’s thought and by an internal way into the organ of hearing and thus actuates it from within, whereas the speech of a person flows first into the air and by an external way into the organ of hearing which it actuates from without. Hence, it is evident that the speech of an angel and of spirit with a person is heard in the person, and since it equally affects the organ of hearing, that it is equally sonorous.” (Emmanuel Swedenborg)