Audio jacks can be seen occupying different places from top to bottom and left to right in different phone designs. There is a recent move of audio jacks to the bottom of the phone, which might as well be a hardware design restriction.
Is there an optimal position of a headphone jack on a phone?
A conclusive opinion on this case would be subjective. However, it can be safely noted that over the years the jack has apparently found a position which provides users the best experience, the topside. By not placing the jacks on either the left or the right sides, the phone could be classified as truly ambidextrous, and would be easier to handle. The "uncomfortabilities" caused by keeping the jack at the bottom side are surprisingly many. It'd be comparatively difficult to hold the phone in hand while the earphone is plugged in, and if you want to slide it into a pocket of some sort, you'd have to go 'head-first'.
The experience can be enhanced by putting the charging port and the head phone jack at the opposite sides (unless they use the same one), so that a muscle memory is involuntarily created to assist the user in remembering what goes where.
