Supplemental alert generation device with speaker enclosure assembly

A method performed by a battery-powered supplemental alert generation device to detect an audible alert signal generated by a detector/alert device, the method comprising:

• passively converting sound into an electrical signal using a piezoelectric sensor;
• monitoring the electrical signal to determine whether a threshold sound level is met;
• in response to determining that the threshold sound level is met, analyzing the electrical signal with signal processing circuitry to determine whether the electrical signal represents the audible alert signal, wherein analyzing the electrical signal comprises determining whether the electrical signal has a pulse pattern corresponding to a pulse pattern used for audible alert signals;
• in response to determining that the electrical signal has a pulse pattern corresponding to a pulse pattern used for audible alert signals, outputting, to a speaker enclosure assembly that comprises an audio speaker mounted to a speaker enclosure structure, a supplemental alert signal having a fundamental frequency and a plurality of higher frequency harmonics, said fundamental frequency falling in the range of 400 to 700 hertz, said speaker enclosure assembly having an object resonance falling in the range of 400 to 700 hertz;
• and
• outputting an audible representation of the supplemental alert signal with the speaker enclosure assembly, wherein outputting the audible representation comprises producing a low frequency audio output boost at least partly by transferring energy in at least one of said harmonics downward in frequency, wherein the speaker enclosure assembly is sealed, such that the low frequency audio output boost is produced without reliance on a flow of as into or out of an enclosure chamber of the speaker enclosure assembly.

A supplemental alert generation device comprising:

• a speaker enclosure assembly comprising an audio speaker mounted to a speaker enclosure structure, said audio speaker comprising a diaphragm that is driven by a coil to produce sound waves corresponding to a received audio signal, said speaker enclosure assembly having an object resonance in the range of 400 to 700 hertz, said object resonance being dependent upon physical dimensions of the speaker enclosure structure;
• and
• processing circuitry that is configured to detect an audible alert signal generated by a detector/alert device, and to respond to the audible alert signal by driving the audio speaker with a supplemental alert audio signal having a fundamental frequency and multiple harmonic frequencies, said fundamental frequency falling in the range of 400 to 700 hertz;
• said speaker enclosure assembly configured to cause energy in the supplemental alert audio signal to be transferred downward in frequency from at least one of the harmonic frequencies, wherein the speaker enclosure assembly is sealed, such that the transfer of energy occurs without reliance on a Helmholtz effect.