HBP The memory in the cave... is Snape's.

[houyhnhnm102]

No: HPFGUIDX 138017

Vivian:

> When Harry finds it and destroys it, Voldemort
> will know because he will feel himself 
> becoming more human. That is when Voldemort will 
> then go to the cave 
> to see what the potion reveals.   

houyhnhnm:

"Does Voldemort know when a Horcrux is destroyed, sir?  Can he feel
it?" Harry asked, ignoring the portraits.

"A very interesting question, Harry.  I believe not.  I believe that
Valdemort is now so immersed in evil and these crucial parts of
himself have been detached for so long, he does not feel as we do. 
Perhaps, at the point of death, he might be aware of his loss...but he
was not aware, for instance, that the diary had been destroyed until
he forced the truth out of Lucius Malfoy." (HBP, AE, p. 507-508)