Patent ID: 8704671

Claim:
A water-resistant or water-proof device for in use being vibrationally coupled to a toilet tank of the type having at least one wall defining therein a water-holding cavity containing a fill valve that automatically refills the toilet tank, turbulence or water entering the tank cavity resulting in wide spectrum noise within and around the tank causing the tank to produce vibrations, the water-resistant or water-proof device comprising: a water-resistant or water-proof enclosure structured to be acoustically coupled to the toilet tank, the enclosure in use conducting translational vibrations produced by the toilet tank, the enclosure being dimensioned and configured to define a resonant cavity therein that is acoustically coupled to the toilet tank and separated by the toilet tank wall from the toilet tank cavity, the resonant cavity defined by the enclosure in use supporting sympathetic resonant vibrations excited by the conducted translational vibrations, the resonant cavity supporting oscillations at a characteristic frequency that falls within the frequency band of the wide spectrum noise generated within and around the toilet tank, the oscillations-exciting air within the resonant cavity to resonate and provide a resonance power spectrum; and a transducer disposed within the enclosure and vibrationally coupled to the resonant cavity, the resonance power spectrum resulting in the transducer being subjected to vibrational energy enhanced by said resonance, the transducer having a response bandwidth, the transducer producing a signal responsive to the conducted translational vibrations and the sympathetic resonant vibrations, wherein the resonant cavity is tuned so that its resonant frequency is at or near the response bandwidth of the transducer to provide increased signal-to-noise ratio of the signal produced by the transducer in response to said toilet tank vibrations.