IanB said:But look what it creates for players - it doesn't encourage caution; it just gives them a no-win situation.
Listen at doors? Get attacked by ear seekers. *Don't* listen at doors? Get ambushed by whatever you were trying to hear in the first place.
Not only that, avoiding ear seekers required metagaming on the part of the PCs. If their characters didn't know about them, there's no reason they should have feared listening at doors. And if they didn't metagame, they ended up with a dead PC.
They really were terribly designed monsters.