From your past experience you know that light can be reflected by a mirror or any other object which has a very smooth or highly polished surface. Those of you who live in a city undoubtedly have noticed that sunlight reflected from a nearby window may brighten a room in your home almost as well as if the sun were shining directly into it.
In somewhat the same way as light is reflected sound can be reflected. Most hard surfaces are good reflectors of sound. However, the reflecting surface need not be smooth or highly polished. Even the side of a hill will reflect sound.