Soundbug is a small speaker that can turn a resonant flat surface into a flat panel speaker. The Soundbug is attached to a smooth

resonant Resonance is a phenomenon that occurs when an object or system is subjected to an external force or vibration whose frequency matches a resonant frequency (or resonance frequency) of the system, defined as a frequency that generates a maximu ...

surface. This surface then acts as speaker. The tone differs depending on the surface (wood, metal, glass etc.). The Soundbug was developed by FeONIC Technology (formerly Newlands Scientific), a commercial research and development company specialising in

magnetostrictive Magnetostriction is a property of magnetic materials that causes them to change their shape or dimensions during the process of magnetization. The variation of materials' magnetization due to the applied magnetic field changes the magnetostrictive ...

audio products as a spin-off from

Hull University The University of Hull is a public research university in Kingston upon Hull, a city in the East Riding of Yorkshire, England. It was founded in 1927 as University College Hull. The main university campus is located in Hull and is home to the Hu ...

. FeONIC used the same technology for Whispering Windows, which is able to resonate shop windows. Soundbug transmits the audio signal to the flat surface by way of a small piece of

Terfenol-D Terfenol-D, an alloy of the formula (''x'' ≈ 0.3), is a magnetostrictive material. It was initially developed in the 1970s by the Naval Ordnance Laboratory in the United States. The technology for manufacturing the material efficiently was de ...

, which is a

alloy of rare earth metals and iron. This material, when stimulated with an electrical input, causes the Terfenol to expand slightly, resulting in sound output with a very small amplitude. Once attached to a flat surface, Soundbug will translate electric signals into mechanical energy, causing the flat surface to vibrate and broadcast the sound.

External links

Soundbug Whispering Windows and Invisible Speakers from FeONICWhispering Windows websiteYouTube video showing Whispering Windows and SoundBug in actionBug sets windows shaking
BBC, 18 March 2002 Sound technology {{Electronics-stub