Chapter V of The Navidson Record discusses echoes both in mythic and scientific terms. Zampano explains how echoes can return words with a different meaning than what they are echoing, and also how echoes can be comforting, as well as their use in terms of echolocation and relation to other senses. All of this seems very unrelated to the previous chapters, until after the discussion of echolocation, towards the end of the chapter. This passage returns the chapter to the focus of previous ones: "Unfortunately, humans lack the sophisticated neural hardware present in bats and whales. The blind must rely on the feeble light of fingertips and the painful shape of a cracked shin. Echolocation comes down to the crude assessment of simple sound modulations, whether in the dull reply of a tapping cane or the low, eerie flutter in one simple word - perhaps your word - flung down empty hallways long past midnight."
In his notes, Truant says that he would have recommended skipping the entire chapter were it not for that part, noting how personal the subject must have been for Zampano and how the passage seems to attack you after the preceding part of the chapter. Indeed, considering his blindness does seem to add a sense that the old man was speaking from experience here. But despite this, something about the passage is more sinister than the mere experience of blindness. In particular, the last few phrases are haunting: "... or the low eerie flutter in one simple word - perhaps your word - flung down empty hallways long past midnight." The first part of the phrase seems to recount how echoes can change words, reflecting only a part of a word, or otherwise changing the meaning entirely. The echo is no longer a mere repetition (though repetition itself can be terrifying), it is the voice of the unknown, the Other, who dwells in the darkness seeking to devour. Though unseen, its presence is felt. This in particular recalls Truant's experience in the shop of some nameless and invisible horror stalking him, only to disappear back into the darkness. Another thing to consider is the nature of the word; how is it yours? Is it simply the word you have uttered, or is it something more? It could be the word spoken by someone else to you, or a word that holds meaning for you. Though perhaps these would not be encountered in empty hallways. What moreover, would such a word be? "Hello"? Or perhaps something else? Either way the word is a weapon; it is 'flung' at the darkness. Is it a shout, violent so as to merit being flung? No, shouts do not have low eerie flutters. It seems to be a reluctant word, thrust quietly in an attempt to drive back the Other.
Why is this strange passage here, and why is it more than it seems? It is here to bring things back on track, to make sure we have not forgotten about the Other; to show that even in a discussion of such innocuous things as echoes, it is still there, waiting.