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 describes the phenomenon of increased amplitude that occurs when the frequency of an applied periodic force (or a Fourier component of it) is equal or close to a natural frequency of the system on which it acts. When an oscilla ...

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 (cf. electrostriction) 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 chan ...

audio products as a spin-off from

Hull University , mottoeng = Bearing the Torch f learning, established = 1927 – University College Hull1954 – university status , type = Public , endowment = £18.8 million (2016) , budget = £190 million ...

. 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 d ...

, 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