The army works in sections, platoons, and similar groups, often with machine and submachine guns, etc. It is unlikely that one ping would encourage a charge by the enemy, even if they could hear it at the distance they would be - rifle shooting distance - as the rest of the group would still be there. House clearing is never alone, who is with you in the foxhole, etc. I would imagine the ping would have been rectified if it had been that much of an issue.