Speech privacy system and/or associated method

• US 10,304,473 B2
• Filed: 03/15/2017
• Issued: 05/28/2019
• Est. Priority Date: 03/15/2017
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Inventors: Krasnov, Alexey
• Primary Examiner(s): Desir, Pierre Louis
• Assistant Examiner(s): Wang, Yi Sheng
• Application Number:
  US15/459,273
• Publication Number:
  US 20180268835A1
• Time in Patent Office: 804 Days
• CPC Class Codes: G10K 11/175 using interference effects; Masking sound
• CPC Class Codes: G10K 11/1754 Speech masking
• CPC Class Codes: G10L 21/003 Changing voice quality, e.g. pitch or formants
• CPC Class Codes: G10L 21/16 Transforming into a non-visible representation devices or methods enabling ear patients to replace direct auditory perception by another kind of perception A61F11/04
• CPC Class Codes: G10L 25/18 the extracted parameters being spectral information of each sub-band
• CPC Class Codes: G10L 25/48 specially adapted for particular use
• CPC Class Codes: G10L 25/87 Detection of discrete points within a voice signal
• CPC Class Codes: H04K 2203/12 for acoustic communication
• CPC Class Codes: H04K 3/41 characterized by the control of the jamming activation or deactivation time control of jamming activation and deactivation time only for the purpose of alternating between jamming mode and target monitoring mode H04K3/45
• CPC Class Codes: H04K 3/45 characterized by including monitoring of the target or target signal, e.g. in reactive jammers or follower jammers for example by means of an alternation of jamming phases and monitoring phases, called "look-through mode"
• CPC Class Codes: H04K 3/46 characterized in that the jamming signal is produced by retransmitting a received signal, after delay or processing
• CPC Class Codes: H04K 3/825 by jamming
• CPC Class Codes: H04K 3/84 related to preventing electromagnetic interference in petrol station, hospital, plane or cinema

Abstract

Certain example embodiments relate to speech privacy systems and/or associated methods. The techniques described herein disrupt the intelligibility of the perceived speech by, for example, superimposing onto an original speech signal a masking replica of the original speech signal in which portions of it are smeared by a time delay and/or amplitude adjustment, with the time delays and/or amplitude adjustments oscillating over time. In certain example embodiments, smearing of the original signal may be generated in frequency ranges corresponding to formants, consonant sounds, phonemes, and/or other related or non-related information-carrying building blocks of speech. Additionally, or in the alternative, annoying reverberations particular to a room or area in low frequency ranges may be “cut out” of the replica signal, without increasing or substantially increasing perceived loudness.

Claims

1. A method for disrupting speech intelligibility, the method comprising:

receiving, via a microphone, an original speech signal corresponding to original speech;

subjecting the original speech signal to a filter, output from the filter being indicative of whether consonants are present in the original speech signal such that the original speech is likely to cause disruption to humans in an area of interest; and

conditioned on output from the filter indicating that consonants are present in the original speech signal such that the original speech is likely to cause disruption to humans in the area of interest;

generating an intelligibility-disrupting masking signal from the original speech signal, the intelligibility-disrupting masking signal being different from the original speech signal by virtue of being generated to have (a) a time delay relative to the original speech signal, (b) the time delay changing according to an oscillation frequency, and (c) an amplitude that is modulated;

causing the intelligibility-disrupting masking signal to be outputted through a speaker to reduce the level of intelligibility of the original speech signal; and

ceasing generation of the intelligibility-disrupting masking signal responsive to output from the filter indicating that the original speech is no longer likely to cause disruption to humans in the area of interest.

2. The method of claim 1, wherein the time delay is at least 80 ms.

3. The method of claim 2, wherein the oscillation frequency adjusts the time delay at a rate of 2-6 Hz.

4. The method of claim 1, wherein output from the filter is indicative of consonants being present in the original speech signal such that the original speech is likely to cause disruption to humans in an area of interest in response to the filter determining that the original speech signal includes frequencies above a threshold.

5. The method of claim 4, wherein the threshold is 1.2 kHz.

6. The method of claim 1, wherein the intelligibility-disrupting masking signal'"'"'s amplitude oscillates from 10-100% of the original speech signal'"'"'s amplitude.

7. The method of claim 1, wherein the intelligibility-disrupting masking signal'"'"'s amplitude oscillates from 40-90% of the original speech signal'"'"'s amplitude.

8. The method of claim 1, further comprising outputting, through the speaker, the intelligibility-disrupting masking signal together with a prerecorded mix of multiple voices.

9. The method of claim 8, wherein the prerecorded mix of multiple voices comprises 2-7 different voices.

10. The method of claim 1, wherein the intelligibility-disrupting masking signal is generated such that gain corresponding to the intelligibility-disrupting masking signal added to the original speech signal is 0.05-0.25%.

11. The method of claim 1, wherein the intelligibility-disrupting masking signal is generated to lack frequencies that otherwise would trigger pre-measured area-specific reverberation modes in the area of interest while maintaining or substantially maintaining the initial level of loudness.

12. The method of claim 11, wherein the frequencies lacking compared to the original speech signal match the pre-measured area-specific reverberation modes.

13. The method of claim 11, wherein the frequencies lacking compared to the original speech signal are in a range of 20-200 Hz.

14. A speech intelligibility disrupting device, comprising:

control circuitry configured to;

receive, from a microphone, an original speech signal corresponding to original speech;

subject the original speech signal to a filter, output from the filter being indicative of whether consonants are present in the original speech signal such that the original speech is likely to cause disruption to humans in an area of interest; and

conditioned on output from the filter indicating that consonants are present in the original speech signal such that the original speech is likely to cause disruption to humans in the area of interest;

generate an intelligibility-disrupting masking signal from the original speech signal, the intelligibility-disrupting masking signal being different from the original speech signal by virtue of being generated to have (a) a time delay relative to the original speech signal, (b) the time delay changing according to an oscillation frequency, and (c) an amplitude that is modulated;

cause the intelligibility-disrupting masking signal to be outputted through a speaker to reduce the level of intelligibility of the original speech signal; and

cease generation of the intelligibility-disrupting masking signal responsive to output from the filter indicating that the original speech is no longer likely to cause disruption to humans in the area of interest.

15. The device of claim 14, wherein the time delay is at least 80 ms.

16. The device of claim 15, wherein the oscillation frequency adjusts the time delay at a rate of 2-6 Hz.

17. The device of claim 14, wherein output from the filter is indicative of consonants being present in the original speech signal such that the original speech is likely to cause disruption to humans in an area of interest in response to the filter determining that the original speech signal includes frequencies above a threshold.

18. The device of claim 14, wherein the intelligibility-disrupting masking signal'"'"'s amplitude oscillates from 40-90% of the original speech signal'"'"'s amplitude.

19. The device of claim 14, wherein the control circuitry is further configured to cause the speaker to output, together with intelligibility-disrupting masking signal, a prerecorded mix of multiple voices.

20. The device of claim 14, wherein the intelligibility-disrupting masking signal is generated to lack frequencies that otherwise would trigger pre-measured area-specific reverberation modes in the area of interest while maintaining or substantially maintaining the initial level of loudness.

21. A speech intelligibility disrupting system, comprising:

a microphone;

a speaker; and

control circuitry configured to;

receive, from the microphone, an original speech signal corresponding to original speech;

subject the original speech signal to a filter, output from the filter being indicative of whether consonants are present in the original speech signal such that the original speech is likely to cause disruption to humans in an area of interest; and

conditioned on output from the filter indicating that consonants are present in the original speech signal such that the original speech is likely to cause disruption to humans in the area of interest;

generate an intelligibility-disrupting masking signal from the original speech signal, the intelligibility-disrupting masking signal being different from the original speech signal by virtue of being generated to have (a) a time delay relative to the original speech signal, (b) the time delay changing according to an oscillation frequency, and (c) an amplitude that is modulated;

cause the intelligibility-disrupting masking signal to be outputted through the speaker to reduce the level of intelligibility of the original speech signal; and

cease generation of the intelligibility-disrupting masking signal responsive to output from the filter indicating that the original speech is no longer likely to cause disruption to humans in the area of interest.

22. An acoustic wall, comprising the system of claim 21.