What does "heard" mean in "I allow fish and meat that is pure in three respects: One has not seen, heard, or suspected..." In Vinaya, there is this rule (copied from Buddhist Monastic Code II):


  "One should not knowingly consume meat killed on purpose (for a
  bhikkhu). Whoever should consume it: an offense of wrong doing. I
  allow fish and meat that is pure in three respects: One has not seen,
  heard, or suspected (that it was killed on purpose for a bhikkhu)." —
  Mv.VI.31.14


How should we interpret "heard"? I can think of some possibilities:


Heard from someone that it was killed for me, i.e., someone told me that it was killed for me.
Heard the sound of killing, e.g. sound of the animal or action of killing
Both of the above.
This translation says,


  If a bhikkhu sees, hears or suspects that it has been killed for him, he may not eat it.


This commentary says,


  Furthermore, even cooked fish or meat of an allowable kind is unallowable if the 
  bhikkhu sees, hears, or suspects that the animal was killed specifically for the 
  purpose of feeding bhikkhus.


Both of these imply only the first of your two possibilities.