Device and method for analysis and filtration of sound

• US 6,243,671 B1
• Filed: 01/04/1999
• Issued: 06/05/2001
• Est. Priority Date: 07/03/1996
• Status: Expired due to Fees

• Current Assignee: Lagö, Thomas, Sven Olsson
• Original Assignee: Lagö, Thomas, Sven Olsson
• Inventors: Lagö, Thomas, Olsson, Sven
• Primary Examiner(s): Korzuch, William R.
• Assistant Examiner(s): Lerner, Martin
• Application Number:
  US09/224,942
• Time in Patent Office: 883 Days
• Field of Search: 704/203, 704/205, 704/226, 704/227, 704/228, 704/233, 704/232, 704/200.1, 381/94.1, 381/94.2, 381/94.3
• US Class Current: 704/200.1
• CPC Class Codes: G01H 3/08 Analysing frequencies present in complex vibrations, e.g. comparing harmonics present acoustic presence detection G01V1/001
• CPC Class Codes: G10L 15/08 Speech classification or search
• CPC Class Codes: G10L 25/18 the extracted parameters being spectral information of each sub-band
• CPC Class Codes: G10L 25/30 using neural networks
• CPC Class Codes: G10L 25/51 for comparison or discrimination
• CPC Class Codes: H03H 21/0012 Digital adaptive filters

Abstract

A device for analysis and filtration of sound which comprises at least one frequency-linear filter, at least one frequency-logarithmic filter and a weighting means for the combining and non-linear weighting of the output signals from the frequency-linear filter and the frequency-logarithmic filter. The sound is fed parallel as an input signal to the two sets of filters. In turn, the output signals from the filters are fed to the weighting means where they are combined and weighted non-linearly on the basis of magnitudes relevant to the sound. A decision with respect to the identity of the sound is made in a decision means. The invention also relates to a method for analyzing and filtering sound with the aid of the above-mentioned device.

Claims

1. A device for analysis and filtration of sound, which device receives an input signal characterised in that it comprises at least one frequency-linear filter, at least one frequency-logarithmic filter for parallel filtration of the input signal, and a weighting means for combination and non-linear weighting of the output signals from the frequency-linear filter and the frequency-logarithmic filter.

2. A device according to claim 1, characterised in that the weighting means consists of a neural net.

3. A device according to claim 2, characterized in that the frequency-linear filter consists of 800 lines.

4. A device according to claim 2, characterised in that the frequency-logarithmic filter consists of 32 one-third octave bands.

5. A device according to claim 2, characterized in that it comprises a decision means for making a decision with respect to the identity of an input signal.

6. A device according to claim 1, characterised in that the frequency-linear filter consists of 800 lines.

7. A device according to claim 3, characterized in that the frequency-logarithmic filter consists of 32 one-third octave bands.

8. A device according to according to claim 3, characterized in that it comprises a decision means for making a decision with respect to the identity of an input signal.

9. A device according to claim 1, characterised in that the frequency-logarithmic filter consists of 32 one-third octave bands.

10. A device according to according to claim 4, characterized in that it comprises a decision means for making a decision with respect to the identity of an input signal.

11. A device according to claim 1, characterised in that it comprises a decision means for making a decision with respect to the identity of an input signal.

12. A device according to claim 11, characterised in that the weighting means comprises the decision means.

13. A method for analysing and filtering sound, characterised by the following steps:

filtering the sound signal parallel in a frequency-linear filter and a frequency-logarithmic filter; and

combining and non-linearly weighting the parallel output signals from the frequency-linear filter and the frequency-logarithmic filter by means of a weighting means.