Speakers Speak & Sing Too Much ???

On some recordings I can hear a split second repeat of the singer's or musician faint coming through the speakers. This is after hearing the recording . *It's only a split second but it's subtle.

This mainly happens on some of the Blue Note & Fantasy Jazz CD recordings.

Is my system out of phase ? Or some kind of feedback or conflict. Ss there something else wrong ? Or is this normal with certain older recordings ? And again this only happens once in awhile with mainly some older late 50's & 60's recordings remastered on CD. I evem changed cables and currently running balanced throughout.

Am I going nuts ??
I remember something like this effect on records when I was a kid (in the 70s), on inexpensive systems, although I think the faint sound happened slightly before the real sound. I don't know what caused it, and I can't remember hearing it on any CDs. I don't know if the effect I heard is from the same cause as your experience. Perhaps the CDs were mastered from records? Or perhaps it is a result of analog reverb machines? I wish I knew, but it brings back memories.
This phenomenon is associated with what recording engineers call tape bleed through. When a recording is made and stored on a Master, after a period of time, because the tape is magnetic and is wound tightly in a reel, the signal can actually "bleed through" to the overlaying tape and be heard as a ghosting of the image to come.
It's echo or pre-echo (if it comes before the real signal) due to print through on the master tape. It's very audible on early Led Zeppelin before Plant screams.
There used to be something called print-through on tapes. When tapes were kept unused for too long, the magnetic signal from the second layer of the winding would slightly magnetize the top layer tape. If the top layer was blank, as at the beginning of a song, you could hear the first bars of the song as a faint print-through signal on the blank lead-in before the song actually started.

There was a similar, though more rare, effect with LPs. If the grooves were cut tightly spaced, the first bars of a song could be slightly modulating the "silent" lead-in groove just ahead of it. This imperfection was quite rare, and what we often heard was actually the LP's reproduction of print-through on the master tape.

On your CDs, I would guess you are hearing print-through from the master tapes. Perhaps careful engineering should have muted this out during production of the CD. Of course, you could in fact be going nuts and imagining the whole thing.