Method of measuring amount of substances in an ambient noise environment

1. A method comprising:

transmitting an acoustic signal through a liquid substance within a container, the container being subject to an ambient noise, the acoustic signal being transmitted through a volume of the liquid substance prior to an interaction between the acoustic signal and a surface of the container;

receiving the acoustic signal after a propagation of the acoustic signal through the volume of the liquid substance;

reducing an ambient noise component of the acoustic signal;

determining an acoustic signature of the acoustic signal having the reduced ambient noise component, wherein the acoustic signature is at least partially based upon a detected frequency spectrum of the acoustic signal propagated through the volume of the liquid substance; and

determining a volume of the liquid substance in the container by comparing the acoustic signature with an acoustic signature of an acoustic signal propagated through a known volume of the liquid substance.

2. The method of claim 1 , wherein generating the excitation signal includes generating the excitation signal within a portion of the container.

3. The method of claim 1 , wherein generating the excitation signal includes generating the excitation signal within a portion of the liquid substance.

4. The method of claim 1 , wherein ambient noise includes sound primarily external to the container.

5. The method of claim 1 , wherein ambient noise includes sound generated by the container other than in response to the excitation signal.

6. The method of claim 1 , wherein the ambient noise includes a sound generated by a resonance of the container independent of the excitation signal.

7. The method of claim 1 , wherein the ambient noise includes a sound proximate to the container other than the excitation signal.

8. The method of claim 1 , wherein receiving the acoustic signal includes receiving the acoustic signal within a portion of the liquid substance.

9. The method of claim 1 , wherein receiving the acoustic signal includes receiving the acoustic signal within a portion of the container not occupied by the liquid substance.

10. The method of claim 1 , wherein reducing the ambient noise component includes modifying the received acoustic signal in response the signal representative of the ambient noise.

11. The method of claim 10 , wherein modifying the received acoustic signal in response the signal representative of the ambient noise includes subtracting a signal representative of the ambient noise from the received acoustic signal.

12. The method of claim 1 , wherein reducing the ambient noise component comprises:

receiving a signal representative of the ambient noise; and

modifying the received acoustic signal in response to the signal representative of the ambient noise.

13. The method of claim 12 , wherein the signal representative of the ambient noise and the acoustic signal are received by the same acoustic receiver.

14. The method of claim 12 , wherein the signal representative of the ambient noise is obtained at a time when the excitation signal is absent.

15. The method of claim 12 , wherein the signal representative of the ambient noise includes a saved signal representative of the ambient noise.

16. The method of claim 1 , wherein reducing the ambient noise component includes application of a convolving algorithm to the acoustic signal.

17. The method of claim 1 , wherein determining the volume of the liquid substance in the container by comparing the acoustic signature with an acoustic signature of an acoustic signal propagated through a known volume of the liquid substance includes:

comparing the detected frequency spectrum of the acoustic signal propagated through the liquid substance with a list of spectra including at least one frequency spectrum associated an acoustic signal propagated through a known volume of the liquid substance.

18. The method of claim 17 , wherein the list of spectra includes a spectrum look-up table.

19. The method of claim 1 , further including providing a volume signal representative of the determined volume.

20. A computer-readable media containing computer instructions which, when run on a computer, cause the computer to perform the method of claim 1 .

21. The computer-readable media of claim 20 , wherein the computer-readable media includes a computer storage media.

22. The computer-readable media of claim 21 , wherein the computer storage media is carried by a computer readable carrier.

23. The computer-readable media of claim 20 , wherein the computer-readable media includes a communications media.

24. A method comprising:

transmitting an acoustic signal through a liquid substance within a container, the container being subject to an ambient noise, the acoustic signal being transmitted through a volume of the liquid substance prior to an interaction between the acoustic signal and a surface of the container;

receiving the acoustic signal after a propagation of the acoustic signal through the volume of the liquid substance;

detecting at least one frequency of the acoustic signal; and

determining the volume of the liquid substance in the container by comparing the detected at least one frequency of the acoustic signal with at least one frequency corresponding to a propagation of the acoustic signal through a known volume of the liquid substance.