When speaking here of primal principles and primal forces, don't imagine these terms to have been abstract constructs with Kirpal Singh. For him, 'light' and 'sound' were immediate experiences, yes, and even psychically experienced phenomena, really very similar to the psychoanalytic drives (especially their 'primary process'1). When sitting in meditation in a dark room for a longer period of time, your mood, body image, awareness of yourself 'light up' to the point of 'light-like' visibility and of something that begins to 'sound', as if the thoughts you have become transparently clear and audible. Surely, such an experiment may require much time and sound guidance,
because otherwise it wouldn't be distinguishable from a psychosis (hallucinatory like experiences).
But Kirpal Singh's yoga has a long tradition which reaches back to Vedian origins.2 One cannot say that it functions with dangerous psychic experiences, even when describing some of the problems disciples of Surat Shabd Yoga had later on. I will only be demonstrating how such 'light' and 'sound', such reflection (mirroring) and resonance (echoing), can be verified in psychoanalysis in the form of the scopic-drive (perception drive) and in the drive to speak (invocation drive), just as their primary process can be experienced (which is not usual in daily psychoanalytic practice, but will be clearly conceptualized in the following).
At any rate, comparative research that only establishes on the formalities of Kirpal Singh's birth, his physical life, or even just Hindu tradition, would not suffice his nature. A scientific comparison is necessary.
1 The "primary process" of the drives is not normally capable of being experienced in psychoanalysis. It remains hidden, unconscious. Only its psychic representation can be experienced. Yoga addresses this subject with a highly reduced form of it, namely 'light' and 'sound'.
2 Veda is known as wisdom in old Indian philosophy.
