StephanotisI have a blind friend who owns a stephanotis which has refused to bloom since the mass of flowers it had when she bought it

Hmm, well there aren't any really. Hyacinths, obviously, in spring, scented jasmine as a temporary visitor (used as a houseplant). Stephanotis is quite fussy (as is Gardenia). Does well in conservatories normally, so long as they don't get too cold at night.
It needs average warmth (no lower or higher than 55-60 deg F during winter though), a brightly lit spot away from direct summer sun, though winter sun is fine. Compost should not be allowed to dry out, but the plant shouldn't be sitting in water, reduced watering winter, very sparing then. During spring summer, requires increased humidity, so a pebble tray with water beneath helps with that. Misting leaves occasionally also helps. Needs repotting yearly or bi yearly, in spring, until its in a 9 inch pot - best compost is loam based, so something like John Innes No. 2. Feed in spring and summer with a liquid high potash feed (tomato food will do), but balance this with something like baby bio alternate weeks.
In case you're wondering what I mean by 'pebble tray', it just means a shallow tray or container of some sort that's wider than the pot the plant is in, filled with pebbles, and kept topped up with water. You stand the plant pot on top of the pebbles, so that the bottom of the pot isn't sitting in the water, but is sitting on the stones - the water in the tray evaporates and makes a humid atmosphere for the plant foliage above. I can't think any of this rather onerous care regime will be easy for a blind person though...

Can only think of bulbs for spring, unless your friend would like the smell of scented geranium leaves?

Thank you Bamboo, for all the detailed info, of which I'll take note . I could try to resurrect my friend's plant for her. I doubt she could do all that herself.
Thanks too, Steragram for reinforcing that there isn't anything much that's scented to grow indoors apart from hyacinths. What a pity that is for blind people! I suppose they have to rely on cut flowers such as lilies and sweet peas.