With proper care and maintenance your hearing aids should give you many years of quality hearing enjoyment. Generally speaking, hearing aids should last for at least five years, but will start to wear out after about three.
After this time, your hearing sensitivity may have changed, new and better technology is usually available, and the old hearing aids seem to always need repair. Hearing aids can be repaired; however, the older the hearing aid the costlier it becomes to repair it, and it typically will continue to break down.
If you are having any difficulty at all in hearing the things you want to hear, it is definitely time to try a set of new hearing aids.