Method of selectively broadcasting classes of signals while attenuating other classes
A method is disclosed which includes receiving an incoming time-varying signal as ambient signal, applying a signal cancellation filter to the incoming time-varying signal to thereby generate an attenuated version of the incoming time-varying signal, selectively choosing one or more selected classes of signals to be broadcasted while other signals are to be attenuated, continually applying the incoming time-varying signal to a classifier to identify presence of the one or more selected classes in the incoming time-varying signal, adding a snippet of a pre-recorded signal associated with each of the identified classes to thereby generate a string of signal snippets associated with the identified classes, and repeating in a loop, combining the attenuated version of the received time-varying signal with the repeated string of signal snippets and broadcasting the combination.
1. A method of selectively passing through signals associated with one or more classes of signals while attenuating other signals, comprising:
receiving an incoming time-varying signal as ambient signal by one or more sensors;
applying a signal cancellation filter to the incoming time-varying signal to thereby generate an attenuated version of the incoming time-varying signal;
selectively choosing one or more selected classes amongst a plurality of classes of signals to be broadcasted while other signals are to be attenuated;
continually applying the incoming time-varying signal to a classifier to identify presence of the one or more selected classes in the incoming time-varying signal;
for each of the one or more selected classes identified as being present by the classifier:
adding a snippet of a pre-recorded signal associated with each of the identified classes each followed by a period of substantially no signal to thereby generate a string of signal snippets associated with the identified classes; and
repeating the string of signal snippets in a loop;
combining the attenuated version of the received time-varying signal with the repeated string of signal snippets to thereby generate a time-varying outgoing signal; and
broadcasting the time-varying outgoing signal through one or more transducers.
2. The method of claim 1 , wherein the incoming time-varying signal is a sound signal.
3. The method of claim 2 , wherein the one or more sensors are each a microphone.
4. The method of claim 3 , wherein the one or more transducers are each a speaker in a headphone.
5. The method of claim 1 , wherein the incoming time-varying signal is a wireless signal.
6. The method of claim 1 , wherein the incoming time-varying signal is a wired signal.
7. The method of claim 1 , wherein the step of applying a signal cancellation filter includes
transforming the incoming time-varying signal into a frequency spectrum; and
applying a band-rejection filter to the spectrum.
8. The method of claim 7 , wherein transforming the incoming time-varying signal into the frequency spectrum is based on a Fourier transform of the incoming time-varying signal.
9. The method of claim 8 wherein the Fourier transform is a Fast Fourier transform.
10. The method of claim 8 , wherein the Fourier transform is a discrete Fourier transform.
11. A method of selectively passing through signals associated with one or more classes of signals while attenuating other signals, comprising:
receiving an incoming time-varying signal as ambient signal by one or more sensors;
establishing a time-varying incoming signal spectrum;
selectively choosing one or more selected classes amongst a plurality of classes of signals to be broadcasted while other signals are to be attenuated;
continually applying the incoming time-varying signal to a classifier to identify presence of the one or more selected classes in the incoming time-varying signal;
for each of the one or more selected classes identified as being present by the classifier:
isolating a spectrum associated with the identified class;
combining all isolated spectra associated with all the identified classes as a pass-through spectrum;
removing the pass-through spectrum from the incoming time-variant signal spectrum to thereby generate an all-reject spectrum;
establishing a 180° phase-shifted spectrum of the all-reject spectrum;
applying the all-reject spectrum by the incoming time-variant signal spectrum to thereby generate an all-pass spectrum;
converting the all-pass spectrum to a time-variant outgoing signal; and
broadcasting the time-varying outgoing signal through one or more transducers.
12. The method of claim 11 , wherein the one or more sensors are each a microphone and
wherein the one or more transducers are each a speaker in a headphone.
13. The method of claim 11 , wherein the step of establishing the time-varying incoming signal spectrum includes:
applying a Fourier transform to the incoming time-varying signal, and
wherein the step of converting the all-pass spectrum to the time-variant outgoing signal includes:
applying an inverse Fourier transform to the all-pass spectrum.
14. The method of claim 13 , wherein the Fourier transform is one of a Fast Fourier transform and discrete Fourier transform.
15. The method of claim 14 , wherein the inverse Fourier transform is one of an inverse Fast Fourier transform and an inverse discrete Fourier transform.
16. A method of selectively passing through signals associated with one or more classes of signals while attenuating other signals, comprising:
receiving an incoming time-varying signal as ambient signal by one or more sensors;
establishing a time-varying incoming signal spectrum;
selectively choosing one or more selected classes amongst a plurality of classes of signals to be broadcasted while other signals are to be attenuated;
continually applying the incoming time-varying signal to a classifier to identify presence of the one or more selected classes in the incoming time-varying signal;
for each of the one or more selected classes identified as being present by the classifier:
isolating a spectrum associated with the identified class;
combining one or more bandpass filters associated with each of the isolated spectrum to thereby generating an all-pass spectrum;
converting the all-pass spectrum to a time-variant outgoing signal; and
broadcasting the time-varying outgoing signal through one or more transducers.
17. The method of claim 16 , wherein the step of establishing the time-varying incoming signal spectrum includes:
applying a Fourier transform to the incoming time-varying signal, and
wherein the step of converting the all-pass spectrum to the time-variant outgoing signal includes:
applying an inverse Fourier transform to the all-pass spectrum.
18. The method of claim 17 , wherein the Fourier transform is one of a Fast Fourier transform and discrete Fourier transform.
19. The method of claim 14 , wherein the inverse Fourier transform is one of an inverse Fast Fourier transform and an inverse discrete Fourier transform.