Listening to music with headphones or earbuds provides you with entertainment but isolates you from the world. If you’re relaxing safely at home, a little isolation might be a welcome thing, but it’s not a good idea when walking or exercising outdoors or when working. If you plug the Fuser from Olens Technology between your music source and your headphones, you can enjoy your music while still hearing traffic sounds or your coworkers (or boss) talking to you. The Fuser looks a bit like the older iPod nano with the clip. It has a built-in microphone that mixes ambient sounds into your music, so you’re always aware of what’s happening around you. The built-in battery is good for about 10 hours of music between charges. Olens even says you can use the Fuser with headphones or earbuds and without a music source as a hearing aid when you need a little help hearing the world around you. It’s $29.95.