By AMY JURRIES

Silicon Valley Global, a company started by the founder of RadioShack, makes portable sound generator products that connect to MP3 players and mobile devices via an audio jack. The speaker-like devices can transform “many surfaces into a flat panel speaker.”

For outdoors users, the Tunebug Shake is a vibration speaker touted to turn your helmet into a surround-sound audio system. We all know that it is dangerous to wear headphones while cycling or snowboarding. Well, now the Tunebug Shake — which launches next month for about $120 — allows you to listen to music while still being able to hear what is happening in the environment around you. That’s the claim, at least.

How does it work? Tunebug’s patented “SurfaceSound” technology enables sound waves to pass through the surface of your helmet, turning the helmet shell into a speaker of sorts. It works by changing the electrical energy of digital music into the “mechanical energy” of sound waves, according to the company.

The sound waves are amplified and driven into, through and out of the surface of the helmet. The result is a speaker with 360-degree listening. Normally, vibration speakers like this work best on flat surfaces. I will be interested to test the Tunebug Shake out and see how it works on the curved surface of a helmet.

Weighing 2.4 ounces, the Tunebug Shake connects to your iPod , MP3 player, or mobile phone via Bluetooth. It is mounted on your helmet by either a Velcro strap or “gecko” mount (see ski helmet picture above). The rechargeable battery will last for up to five hours of continuous play, the company cites. It uses a standard USB cable to charge. The Tunebug Shake is water resistant with large buttons for volume controls and power on/off.

The Tunebug Shake will retail for $119.95 and can be pre-ordered from the company website. It will ship on Feb 28th. www.tunebug.com

—Amy Jurries is founder and editor of TheGearCaster.com, a blog dedicated to profiling emerging companies and technologies in the outdoor sports industry.