I think we need to consider a category for solfege. These aren't really vocal exercises (though those are usually called "solfeggietto" because they use solfege), but because they are used for ear training for all musicians, as opposed to specifically vocal training, I think a vocal tag is not quite right.
Any other opinions?
By the way, the page that sparked this idea was:
http://imslp.org/wiki/L%27Enseignement_ ... Andr%C3%A9)#IMSLP237249