What spotting should be made if you can't visually acquire the impact but hear it, and you aren't sure if it's over or short?

The correct response to the situation where you cannot visually acquire the impact but hear it, and you're uncertain if the round is over or short is "Unobserved." This term is used in fire support operations to indicate that the observer is unable to see the landing of the munition, but they may have auditory confirmation of the impact. In this context, "Unobserved" means that while you may know the round has hit based on sound, further verification is needed to determine the exact location and effect of the round on the target.

This scenario typically occurs when visibility is obstructed, or the observer is at a distance where visual confirmation isn't possible, but sound can still be perceived. The term emphasizes the limitation in the observer's situational awareness concerning the fired round, which is critical for assessing effectiveness and providing corrective adjustments if necessary.

The other terms, while they may seem similar, do not accurately describe the situation. "Doubtful" would imply uncertainty about the round's impact without providing clarity on what the observer knows. "Lost" would usually refer to an inability to track or maintain situational awareness of the mission altogether. "Cannot Observe" suggests complete incapacity to observe an impact, which might imply no auditory or visual cues