In the same vein as Torana's Colour Imagery challenge, it occurred to me that sound imagery is often neglected in poetry. Sound imagery? Isn't that an oxymoron? You don't see sounds! No, but imagery encompasses more that description of visual elements. All five senses participate in perception, and good imagery related to the other four senses can greatly enrich the reader's involvement. So select a sound, and try describing it vividly, so a reader will recognize the sound in all its nuances, and tie it to an emotional reaction. Good luck, and have fun with it!