Extremely dependent on context. Like any metaphor it has a wide range of connotations. Think "needle in a haystack."
Finding missing persons in New York is like trying to find a needle in a haystack.
Indentifying the out of tune violin in this orchestra's rendition of Pacabel's Canon is like trying to find a needle in a haystack.
And so forth.
"Lost in the echo" is similar, but more subtle:
Her comments kept reverberating in my mind like a skipping record. Everything that followed was lost in the echo.
This Pinot Noir has won awards, some critics citing it's subtle oaky flavoring, but I think it's overly complicated and the lingering berry flavor is strong. The oak is just lost in the echo.
There may not be a literal translation that captures the concept. I'd be interested to know.