Detecting and monitoring legacy devices (such as appliances in a home) using audio sensing is disclosed. Methods and systems are provided for transforming audio data captured by the sensor to afford privacy when speech is overheard by the sensor. Because these transformations may negatively impact the ability to detect/monitor devices, an effective transformation is determined based on both privacy and detectability concerns.

Covert acoustic communications (CAC) through solid propagation channels that connect node pairs is achieved by encoding signals using spread spectrum coding techniques that position the encoded signal at a center frequency f.sub.c within a narrow frequency bandwidth BW.sub.NB in which the amplitude of the channel response H(f) between each node pair is relatively high. The channel response H(f), bandwidth BW.sub.NB and center frequency f.sub.c, and accordingly the signal data rate will adapt for each node pair and possibly each side of the node pair. A pre-distortion filter 1/H(f) pre-distorts the encoded signal over bandwidth BW.sub.NB to compensate for material and modal dispersion and multipath between the node pair. This technique avoids the problems associated with frequency dependent attenuation of the continuous solid path and allows for simultaneous transmission and reception of signals among the multiple node pairs.

An acoustic sensor is positioned in an environment and configured to generate a data stream responsive to acoustic energy in the environment. A controller is configured to receive the data stream. The controller is further configured to analyze the data stream to determine ambient acoustic signals. The controller is further configured to generate an ambient acoustic template based on the determined ambient acoustic signals. The controller is further configured to apply the ambient acoustic template to the data stream so that the ambient acoustic signals are suppressed in the data stream. The controller is further configured to analyze the data stream after the ambient acoustic signals are suppressed in order to determine if the acoustic energy in the environment includes acoustic energy of human snoring. The controller is further configured to issue a control signal to a second controller in order to engage a home automation device.

A method, for preventing the intelligible voice recording is provided. The voice of a subject or interlocutor is recorded for a given time interval thereby providing a voice recording. The voice recording is cut into shorter time interval segments thereby providing a set of voice recording segments. The set of voice recording segments is mixed in a randomly rearranged order. The mixed set of voice recording segments is spliced into a single randomly mixed voice recording. Emitting the randomly mixed voice recording during speaking of the subject or interlocutor prevents the intelligible recording of the voice of the subject or interlocutor.

A method, for preventing the intelligible voice recording is provided. The voice of a subject or interlocutor is recorded for a given time interval thereby providing a voice recording. The voice recording is cut into shorter time interval segments thereby providing a set of voice recording segments. The set of voice recording segments is mixed in a randomly rearranged order. The mixed set of voice recording segments is spliced into a single randomly mixed voice recording. Emitting the randomly mixed voice recording during speaking of the subject or interlocutor prevents the intelligible recording of the voice of the subject or interlocutor.

Methods and apparatuses for addressing open space noise are disclosed. In one example, a method for masking open space noise includes optimizing a recorded naturally occurring sound signal. The method also includes outputting the optimized recorded naturally occurring sound signal from a plurality of speakers distributed in the open space. Further, the method includes displaying a natural system complementing the optimized recorded naturally occurring sound signal.

Methods and apparatuses for addressing open space noise are disclosed. In one example, a method for masking open space noise includes optimizing a recorded naturally occurring sound signal. The method also includes outputting the optimized recorded naturally occurring sound signal from a plurality of speakers distributed in the open space. Further, the method includes displaying a natural system complementing the optimized recorded naturally occurring sound signal.

A radio transmitter adjusts its radio frequency (RF) fingerprint to defeat RF fingerprinting identification without destroying the content of its transmissions. The radio transmitter comprises a frequency-upconverter configured to upconvert a baseband or intermediate-frequency signal to an RF signal, and an amplifier to amplify the RF signal to produce a transmission signal. An RF fingerprint control circuit changes the non-linear behavior of the frequency-upconverter or the amplifier in order to change the RF fingerprint. The transmitter may create RF fingerprint personalities to be paired with different radio protocol behaviors and subscriber terminal identification codes (e.g., MAC addresses or SMSIs) for generating different radio identities.

Various embodiments of the teachings herein include methods and systems for providing a speech-based service for the control of room control elements in buildings. Speech instructions are received by means of an audio device. The audio device is configured to analyze the received speech instructions, to convert them into corresponding operating commands for room control elements for the control of, in particular, HVAC devices (e.g. field devices) in a building and to pass them on to the corresponding room control elements. Before the receipt of the speech instructions by the audio device, the identity of the sender (user) of the speech instructions is anonymized by means of an anonymization service.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless device may receive a beamformed signal from a transmitting device. The wireless device may estimate a weighted sum based at least in part on one or more coefficients that relate to impairments associated with the transmitting device, a spatial location of the wireless device, and/or the like. The wireless device may determine a cryptographic key based at least in part on a ratio among the plurality of coefficients in the weighted sum, and one or more communications between the wireless device and the transmitting device may be secured based on the cryptographic key. Numerous other aspects are provided.