Abstract: Personal speaker systems including headset and earbud systems may be configured to capture audio data using an in-ear microphone while a speaker outputs known audio signals into the ear canal. The system may generate an acoustic model of the compressed ear canal and ear drum of the listener and utilize the acoustic model to provide noise cancelation at the eardrum, modification to the audio to result in a more natural sound at the eardrum, and/or to measure leakage of the personal speaker system.

Abstract: Personal speaker systems including headset and earbud systems may be configured to capture audio data using an in-ear microphone while a speaker outputs known audio signals into the ear canal. The system may generate an acoustic model of the compressed ear canal and ear drum of the listener and utilize the acoustic model to provide noise cancellation at the eardrum, modification to the audio to result in a more natural sound at the eardrum, and/or to measure leakage of the personal speaker system.

Abstract: Personal speaker systems including headset and earbud systems may be configured to capture audio data using an in-ear microphone while a speaker outputs known audio signals into the ear canal. The system may generate an acoustic model of the compressed ear canal and ear drum of the listener and utilize the acoustic model to provide noise cancelation at the eardrum, modification to the audio to result in a more natural sound at the eardrum, and/or to measure leakage of the personal speaker system.

Abstract: Personal speaker systems including headset and earbud systems may be configured to capture audio data using an in-ear microphone while a speaker outputs known audio signals into the ear canal. The system may generate an acoustic model of the compressed ear canal and ear drum of the listener and utilize the acoustic model to provide noise cancellation at the eardrum, modification to the audio to result in a more natural sound at the eardrum, and/or to measure leakage of the personal speaker system.

Abstract: In some examples, devices for detecting and measures a ghost echo current in an audio signal are described. For instance, the device may be configured to sample a current of an audio signal, compare with an expected current, and determine an impulse response of the ghost echo current based on the sampled current and the expected current. The device may also be configured to reduce the ghost echo current using the impulse response.

Abstract: Devices for monitoring a sound pressure level of sound generated by a speaker. For example, the device may sample voltages at various points along a path of an audio signal, determine a current associated with the audio signal, and receive or infer an efficiency of the speaker. The device may then determine the sound pressure level based on the voltage, the current, and the efficiency to more accurately monitor the sound pressure level exposure of a user.

Abstract: Devices for improving the quality of sound output by a speaker. For example, the device may act to remove ultrasonic frequencies from an audio signal prior to the audio signal being output by a speaker. In other examples, the device may act to impede the progress of harmonic distortion, intermodulation distortion, and environmental noise feeding back into the source device.

Abstract: In some examples, devices for detecting and measures a ghost echo current in an audio signal are described. For instance, the device may be configured to sample a current of an audio signal, compare with an expected current, and determine an impulse response of the ghost echo current based on the sampled current and the expected current. The device may also be configured to reduce the ghost echo current using the impulse response.

Abstract: Devices for monitoring a sound pressure level of sound generated by a speaker. For example, the device may sample voltages at various points along a path of an audio signal, determine a current associated with the audio signal, and receive or infer an efficiency of the speaker. The device may then determine the sound pressure level based on the voltage, the current, and the efficiency to more accurately monitor the sound pressure level exposure of a user.

Abstract: Devices for monitoring a sound pressure level of sound generated by a speaker. For example, the device may sample voltages at various points along a path of an audio signal, determine a current associated with the audio signal, and receive or infer an efficiency of the speaker. The device may then determine the sound pressure level based on the voltage, the current, and the efficiency to more accurately monitor the sound pressure level exposure of a user.

Abstract: An impedance matched resonant circuit uses inductors coupling an audio source and a speaker array in order to reduce feedback reflection induced by an audio signal traveling from the audio source to the array of speakers. An RC circuit could also be coupled to the positive and negative terminals of the speaker array to reduce the slope differential of the audio signal at certain frequencies. The circuit can be packaged together in a single module with switches to activate and deactivate portions of the circuit to alter the effectiveness of the circuit depending upon need.

Abstract: A system and method is provided for determining a channel estimate utilizing partial channel estimates to provide an aggregated channel estimate. A partial channel estimate is determined upon receipt of a data burst, such that a different subset of the channel estimate is updated every data burst. As a result, Fast Fourier Transform computations can be reduced by determining a portion of the channel estimate each data burst as opposed to determining a full channel estimate every data burst.

Abstract: A wireless transmitter (TX1). The transmitter comprises circuitry for providing a plurality of control (CONTROL) bits and circuitry for providing a plurality of user (USER) bits. The transmitter also comprises circuitry for modulating (16) the plurality of control bits and the plurality of user bits into a stream of complex symbols and circuitry (18) for converting the stream of complex symbols into a parallel plurality of complex symbol streams. The transmitter also comprises circuitry (20) for performing an inverse fast Fourier transform on the parallel plurality of complex symbol streams to form a parallel plurality of OFDM symbols and circuitry (22) for converting the parallel plurality of OFDM symbols into a serial stream of OFDM symbols. Each OFDM symbol in the serial stream of OFDM symbols comprises a plurality of data points, and selected (SF2.x) OFDM symbols in the serial stream of OFDM symbols carry modulation information (AMOD).

Abstract: Available quadrature amplitude modulation (“QAM”) carriers transmittable by a base station to customer sites are substantially equally divided among the sites according to the expected quality of reception. ARQ transmissions from the sites are monitored as a measure of the quality of signals received by the sites. If the quality of received signals is unacceptable, the affected site is re-assigned to a higher quality QAM. In addition, if the quality of received signals is too high, the affected site is re-assigned to a lower quality QAM.

Abstract: A wireless transmitter (TX1). The transmitter comprises circuitry for providing a plurality of control (CONTROL) bits and circuitry for providing a plurality of user (USER) bits. The transmitter also comprises circuitry for modulating (16) the plurality of control bits and the plurality of user bits into a stream of complex symbols and circuitry (18) for converting the stream of complex symbols into a parallel plurality of complex symbol streams. The transmitter also comprises circuitry (20) for performing an inverse fast Fourier transform on the parallel plurality of complex symbol streams to form a parallel plurality of OFDM symbols and circuitry (22) for converting the parallel plurality of OFDM symbols into a serial stream of OFDM symbols. Each OFDM symbol in the serial stream of OFDM symbols comprises a plurality of data points, and selected (SF2.x) OFDM symbols in the serial stream of OFDM symbols carry modulation information (AMOD).

Abstract: ARQ is implemented in a fixed wireless communication system utilizing a demand access MAC, such as DOCSIS, and variable length PDUs, such as Ethernet packets, in messages between a base station and CPE. The base station inserts a sequence number into each PDU. The sequence numbers are members of a series, adjacent ones differing by the same factor. The CPE determines if any sequence number/s is/are missing from the packets of a received message, indicating a failure to receive their associated packets. The missing sequence numbers are included in a message back to the base station, which uses them to re-send the missing packets. The series may be generated according to a rule or algorithm available to both the base station and the CPE.

Abstract: Available quadrature amplitude modulation (“QAM”) carriers transmittable by abase station to customer sites are substantially equally divided among the sites according to the expected quality of reception. ARQ transmissions from the sites are monitored as a measure of the quality of signals received by the sites. If the quality of received signals is unacceptable, the affected site is re-assigned to a higher quality QAM. In addition, if the quuality of received signals is too high, the affected site is re-assigned to a lower quality QAM.

Abstract: A system and method is provided for determining a channel estimate utilizing partial channel estimates to provide an aggregated channel estimate. A partial channel estimate is determined upon receipt of a data burst, such that a different subset of the channel estimate is updated every data burst. As a result, Fast Fourier Transform computations can be reduced by determining a portion of the channel estimate each data burst as opposed to determining a full channel estimate every data burst.