Are you thinking about a science project on this topic? Are you planning to use one dog with different sounds or several dogs with the same sound? Your question is too vague to answer specifically. If it is for a science project, you will need to have a sound that can be duplicated exactly the same each time, such as a recording. Many libraries have CDs of various sound effects that could be useful. You will need a way to record the dog's reaction, such as with a video camera.