Patent ID: 8723656

Claim:
A method for producing a location-aiding audible signal, the method comprising: defining a near field location-aiding audible signal comprising broad-bandwidth audible noise with spectral portions selectively modified to create respective spectral amplitude peaks within substantially 1/16 th of an octave around 500 Hz, within substantially 1/16 th of an octave around 4 kHz and within substantially 1/16 th of an octave around 8 kHz; defining a far field location-aiding audible signal comprising a plurality of simultaneously occurring fundamental tone frequencies, the far field location-aiding audible signal further comprising a plurality of respective harmonic components for each fundamental tone frequency; emitting, during each of a first set of time durations, the near field location-aiding audible signal; and emitting, during a second set of time durations, the far field location-aiding audible signal, the second set of time durations being interleaved with the first set of time durations.