Auf der Suspicious Minds - The Memphis 1969 Anthology.
Ich tippe mal den Text der vorletzten Seite des Booklets ab:

Special note: The music track for "Poor Man's Gold" was recorded while Elvis stayed at home with Ianryngitis (Höh? ). When he returned to record his vocals, he was distracted by a fire engine's siren blasting through the studio walls! This went straight on tape - you can hear it by turning up the volume. This disruption ended Elvis' commitment to the song and this small segment is all that was ever recorded of Elvis' vocal.