Patent ID: 8189809

Claim:
An audio device comprising a first audio path comprising a loudspeaker for reproducing an audio signal, and a second audio path comprising in series: a band-pass filter for passing frequency components of the audio signal lying between a first frequency and a second frequency, said first frequency being lower than said second frequency, and for attenuating frequency components of the audio signal lower than said first frequency and higher than said second frequency, a detector for detecting an amplitude of the band-pass filtered audio signal, a multiplier for multiplying a periodic signal having a third frequency by the amplitude of the band-pass filtered audio signal, a vibration device for reproducing the multiplied periodic signal, wherein the third frequency is substantially equal to a resonance frequency of the vibration device, wherein the second audio path further comprises a generator for generating the periodic signal, and wherein the second audio path further comprises a control path arranged between the vibration device and the generator, the generator being adapted to adjust the third frequency in dependence on parameters of the vibration device.