Hi Pauline,
I agree, the fragrance takes a lot of beating!
The Hyacinth's produced by nurserymen for indoor use are speially treated and timed to bloom at the optimum time such as Christmas and will hopefully last for 4 - 6 weeks.
Sadly to get them to flower again indoors, in my oppinion usually will result in failure or dissappointment.
They can though be planted outside and will successfully re-adjust to flowering in the spring.
When the flowers have died back and the leaves have withered, cut it back close to the bulb and plant it in the garden at 3 times the depth of the bulb in a spot where you know it will be safe from being disturbed ie under a tree or shrub, I've had them coming up year after year for longer than I care to remember! To maximise their chances, add some bulb fiber when planting, plus a sprinkling of slow reliese fertilizer and plenty of water.
Good Luck Tbird+