The scheme is still not complete. Let's put all sensory aspects into one table.These are the predicate that we might get (I will give them temporary names in curly brackets).
{HEAR} - x1 hears object(e.g. musician)/event (e.g. concert) x2, listens to it and defines x2 as x3 (noisy, loud, sweet, lovely, romantic etc.)
{SEE} - x1 sees object/event x2, looks at x2 and defines it as x3 (green, that it looks ugly etc.)
{SMELL} - x1 smells object/event x2, observes x2 and defines it as x3 (e.g. flowery,pungent, musk)
{TASTE} - x1 tastes object/event x2, observes x2 and defines it as x3 (e.g. tasty, sweet,sour)
{TOUCH} - x1 touches x2, observes (tries) x2 and defines it as having texture x3 (e.g. rought)
As you can see we actually need valsi with three places. "observe" is a variation of each predicate that can be best expressed using additional {jundi} or {zgana} as xorxes suggested.
This scheme is consistent. The only problem is that it doesn't correspond to the current mess of sensory gismu.
The only gismu that corresponds to this scheme is {te panci}.
{sumne} is a superfluous gismu.
{te tirna} is something that we can also place in every sensory gismu.
{vrusi} overlaps the senses of taste and smell.
This is something that definitely needs revision.
We have five senses and we must clearly express what we feel.
Currently Lojban lacks such power (except in the case of {te panci}).
Addition.
{te skari} also follows this pattern.
However, tirna3, viska3 and skari4 can be easily expressed using {va'o}.