Sorting hat/houses

[CK Campbell]

No: HPFGUIDX 175064

I've been wondering about the sorting hat and Dumbledore's comment to Snape
that perhaps they sort too soon.  I *think* what Dumbledore was saying was
that Snape might have made a good Gryffindor as well -- just as the sorting
hat thought that Harry would make a decent Slytherin but took his preference
and put him in Gryffindor.
 
Surely, there are many children sorted into one house when they could have
done a fine job in other houses.  What if they just don't work out in that
house?  Is it possible, do you think, for the student to change houses?  Or
are you stuck where the sorting hat has put you?  I'd like to think that
Dumbledore would recognize that people change, and that despite the hat's
initial reading of that student, another house might be more suitable.
 
And what of parental influence?  What if Draco had been placed in
Hufflepuff?  Would his parents have been able to get him shifted over to
Slytherin?
 
And here's another question -- and because I can't find my first book I
can't check this out for myself and have only the memory from that other
medium -- does the sorting hat speak aloud?  or does it speak only in the
minds of the students who wear it?
 
Carolyn