SPEECH PRIVACY SYSTEM AND/OR ASSOCIATED METHOD
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.
1 . A method for reducing annoying reverberation in an area having area-specific reverberation modes, the method comprising:
receiving, via a microphone, an original acoustic signal;
generating a replica signal from the original acoustic signal, the replica signal being generated to lack frequencies that otherwise would trigger the area-specific reverberation modes in the area while maintaining or substantially maintaining the initial level of loudness; and
outputting, through a speaker, the replica signal.
2 . The method of claim 1 , wherein the area is a room having at least one glass-inclusive wall or window.
3 . The method of claim 1 , wherein the replica signal is generated such that the frequencies that it is intended to lack compared to the original acoustic signal are cut-off according to a delta-function.
4 . The method of claim 1 , wherein the replica signal is generated such that the frequencies that it is intended to lack compared to the original acoustic signal are cut-off according to a Gaussian distribution.
5 . The method of claim 1 , wherein the replica signal is generated such that the frequencies that it is intended to lack compared to the original acoustic signal match the area-specific reverberation modes.
6 . The method of claim 1 , wherein the replica signal is generated such that the frequencies that it is intended to lack compared to the original acoustic signal correspond to a single fundamental reverberation frequency of the room.
7 . The method of claim 1 , wherein the replica signal is generated such that the frequencies that it is intended to lack compared to the original acoustic signal are in a range of 20-200 Hz.
8 . A system for reducing annoying reverberation in an area having area-specific reverberation modes, comprising:
a microphone;
a speaker; and
control circuitry configured to:
receive, via the microphone, an original acoustic signal;
generate a replica signal from the original acoustic signal, the replica signal being generated to lack frequencies that otherwise would trigger the area-specific reverberation modes in the area while maintaining or substantially maintaining the initial level of loudness; and
output, through the speaker, the replica signal.
9 . The system of claim 8 , wherein the area is a room having at least one glass-inclusive wall or window.
10 . The system of claim 8 , wherein the replica signal is generated such that the frequencies that it is intended to lack compared to the original acoustic signal are cut-off according to a delta-function.
11 . The system of claim 8 , wherein the replica signal is generated such that the frequencies that it is intended to lack compared to the original acoustic signal are cut-off according to a Gaussian distribution.
12 . The system of claim 8 , wherein the replica signal is generated such that the frequencies that it is intended to lack compared to the original acoustic signal match the area-specific reverberation modes.
13 . The system of claim 8 , wherein the replica signal is generated such that the frequencies that it is lacking compared to the original acoustic signal correspond to a single fundamental reverberation frequency of a room in which the system is located.
14 . The system of claim 9 , wherein the replica signal is generated such that the frequencies that it is intended to lack compared to the original acoustic signal are in a range of 20-200 Hz.
15 . The system of claim 8 , wherein the control circuitry comprises a bandpass filter and an amplifier.
16 . The system of claim 9 , wherein the control circuitry is further configured to measure acoustic parameters pertaining to reverberation modes of the area.
17 . The system of claim 9 , wherein:
the control circuitry comprises a bandpass filter and an amplifier;
the control circuitry is further configured to:
measure acoustic parameters pertaining to reverberation modes of the area; and
control the bandpass filter and amplifier to generate the replica signal in accordance with measured acoustic parameters.
18 . The system of claim 17 , wherein a signal from the bandpass filter is fed into the amplifier.
19 . A wall comprising the system of claim 9 .
20 . The wall of claim 19 , comprising glass.