Imagine yelling as loudly as you can and getting nothing back, not even your own echo. That is the situation the speaker describes. The abyss swallows every sound, and the "silent vacuum of time" suggests that the silence is not just empty space but something stretched out and endless. The speaker can't even hear their own voice, which makes the isolation feel total: they are losing proof that they exist at all.
What stands out is how the poem ends. After all that emptiness, the speaker still keeps trying "to make contact / with someone / with something." The shift from "someone" to "something" is telling. It sounds like hope shrinking, as if the speaker will settle for any response at all, human or not. The mood is lonely and bleak, but there is stubbornness in it too. The short, unpunctuated lines feel like breathless, repeated attempts, and the title's image of a lost signal fits a voice that keeps broadcasting without knowing if anyone is listening.