Would there be a preferred loudspeaker design for someone with normal hearing in one ear and none in the other? Let's assume a typical configuration of speakers and listening position. Perception of soundstage becomes irrelevant, but all other considerations should still apply.
I have a friend who has hearing in only one ear. He is a former musician (among other things) and loves music. His loudspeaker of choice is a full-range electrostatic.
He is apparently much more sensitive to phase response than people with hearing in both ears, an area where his single-fullrange-panel SoundLabs presumably perform well (I haven't seen actual phase measurements of them). I don't have data to support this, only an anecdote:
I took a pair of new amplifiers to his house once, and the amplifier designer had bragged to me about how good the phase response was on his amps. I don't remember his exact claim, but it was something like plus or minus 2 degrees across whatever frequency range. I did not mention any of this to my friend, nor would he have had any way of knowing it.
Anyway just a few seconds into the first song he said, "These amps have really good phase response!" This was the first and only time I've heard anyone claim to perceive the phase response of an amplifier, and his stated observation matched the amplifier manufacturer's claims. Needless to say I was amazed.
My sample size is too small for me to say with confidence that people with hearing in only one ear are particularly sensitive to phase response (presumably in loudspeakers as well as amplifiers), but perhaps binaural hearing is more forgiving of phase anomalies.