Stories often have a single "privileged" character through which the world is seen. These characters can be rendered in the 1st, 3rd or (usually unsuccessfully, though "Bright Lights, Big City" (Jay McInerny) might be an exception) 2nd person. But there are also "ensemble" pieces with many equally important "glass-heads". When inside a head the other heads are opaque, so we have a chance to see characters from the inside and outside.
The technique is fairly common in documentaries (clips of several talking heads involved in the same event are spliced together). It works ok in songs like "Penny Lane", and in some films. In novels the point-of-view can easily be changed at a chapter break, and 2 or 3 clearly distinguished time-lines or story-lines are juggled. Less commonly, short numbered sections (or even paragraphs) are used ("if nobody speaks of remarkable things" by Jon McGregor is a recent mainstream UK example).
When the text is broken down into short sections, it's harder to identify the voices, and the narrative stream tends to become a collage. Short stories using this technique have little choice but to risk collage and consequent rejection.
Voice separation is an issue (though not a necessity). In a film like Wings of Desire not only the audio track but also the images help identify the source of the words. In a book like "The Waves" the changes of voice aren't clearly defined, though with practise one begins to identify the characters' style. In some pieces, voice-identification is all part of the literary game that readers are supposed to enjoy. In other pieces I suspect the author's more into creating an ocean-of-consciousness feeling than presenting individuals. Here are 2 quotes from "The Creative Writing Coursebook", Julia Bell & Paul Magrs (eds), MacMillan, 2001
- The key [to changing viewpoints] is to look as though you are in control, and not to apologise or try to disguise what you're doing ... This means establishing your technique near the start and following it confidently", Jenny Newman, p.147
- "If you are going to write multiple viewpoints you want to make sure you have a strong narrative view", Julia Bell, p.164
I like the "The Wasteland" - some of the voices and transitions are more ambiguous than others, but the non-mythical characterisation is clear enough. I think that if the author knows who's saying what (I bet Woolf knew), then the reader might as well be told. Maybe the text should be set out a little like a play script (e.g. as in The Time Traveler's Wife). At least the changes should be clearly shown - by a line across the page, or by centred stars, etc. The reader might well be able to work out the transitions a few words into a new section, but I think that puts the reader at an unfair disadvantage.