Many people with no interest in fish or water plants still enjoy the sound of moving water in their garden. Adding a fountain is easier than you might expect and you don't even need a pond. Small recirculating garden fountains can be tucked into garden beds or featured on your deck or patio. Make sure you choose one that is intended for outdoor use, since it will be exposed to the elements. Many require access to an electrical outlet, but there are more and more battery powered fountains or run on solar power.
If you do have a pond, you'll want to consider how loud a water sound you want from it. You can get a gentle trickle from a shooting fountains or a rhythmic cascade from a natural looking water fall or even a series of falls. More elaborate set-ups may require hiring professionals and are more easily accomplished if they are part of the original design.