Abstract: In an audio network system constructed from a main node and a plurality of satellite nodes each having a plurality of ports, the main node generates and transmits a main packet including audio signals of a plurality of channels. Each satellite node selects one of the plurality of ports in turn, and confirms whether the main packet arrives at the selected port every predetermined period or not. When the main packet arrives at the selected port every predetermined period, the main packet is received via the port by continuing selection of the port. In the case where reception of the main packet is lost, one is selected from the plurality of ports in turn, the operation to confirm arrival of the main packet is restarted, and another port at which the main packet arrives at the present stage is automatically found.

Abstract: In an audio network system constructed from a main node and a plurality of satellite nodes each having a plurality of ports, the main node generates and transmits a main packet including audio signals of a plurality of channels. Each satellite node selects one of the plurality of ports in turn, and confirms whether the main packet arrives at the selected port every predetermined period or not. When the main packet arrives at the selected port every predetermined period, the main packet is received via the port by continuing selection of the port. In the case where reception of the main packet is lost, one is selected from the plurality of ports in turn, the operation to confirm arrival of the main packet is restarted, and another port at which the main packet arrives at the present stage is automatically found.

Abstract: A method of processing a spectrally-encoded digital audio signal comprising band data components representing audio contributions in respective frequency bands comprises the steps of altering a subset comprising one or more of the band data components; and generating recovery data to allow the original values of the altered band data components to be reconstructed.

Abstract: Data processing apparatus comprises an array of user-operable controls, the controls being adjustable by movement of a user's hand while touching a control; a detector for detecting when a user's hand is touching a control; a display screen for displaying respective screen icons associated with the controls; and a display processor, responsive to a detection that a user's hand is touching one of the controls, for altering the screen icon associated with that control.

Abstract: An audio signal processor which modifies audio signal components outside the conventional audio frequency band. The processor includes a Delta Sigma Modulator (DSM) that receives a non-interpolated digital audio signal sampled at a frequency of at least 198 kHz.

Abstract: Apparatus for storing or transmitting a one-bit digital signal comprises an input inverter for inverting a subset of the data bits of an input one-bit digital signal, to generate a bit-inverted signal; a storage or transmission medium for storing or transmitting the bit-inverted signal; and an output inverter for inverting the subset of the data bits of the bit-inverted signal, to regenerate the input one-bit digital signal.

Abstract: A method of processing a spectrally-encoded digital audio signal comprising band data components representing audio contributions in respective frequency bands comprises the steps of altering a subset comprising one or more of the band data components; and generating recovery data to allow the original values of the altered band data components to be reconstructed.

Abstract: An audio signal processor modifies audio signal components over the whole of the frequency range DC to greater than 24 kHz. Preferably the signals are in 1-bit form with a sampling rate in the range about 198 kHz to about 2.8 MHz.

Abstract: Audio processing apparatus comprises one or more touch-sensitive controls for adjusting a gain applied to an audio processing channel in response to movement of a user's hand while touching the controls; a detector for detecting a predetermined sequence of activation of a touch sensitive control by the user; and a signal switch responsive to a detection of the predetermined sequence of activations to toggle between a first mode of operation in which the audio processing channel is operable to suppress an input audio signal and a second mode of operation in which the input audio signal is not suppressed.

Abstract: A signal processor for 1-bit signals comprises a fifth order Delta-Sigma Modulator (DSM) having an input for receiving a 1-bit signal and an output at which a processed 1-bit signal is produced by a quantizer. The quantizer receives a p-bit signal from a series of five signal integration stages. Each stage comprises a first 1-bit multiplier coupled to the input, a second 1-bit multiplier coupled to the output, an adder which sums the outputs of the coefficient multipliers and an integrator which integrates the output of the adder. A final stage comprises a coefficient multiplier and an adder. The adder sums the output of the coefficient multiplier and the output of the integrator of the preceding integration stage. The coefficients are chosen to provide an overall attenuation of the input signal and of the quantization noise produced by the quantizer. Reduction of quantization noise allows several DSMs to be connected in series by preventing the build-up of excess noise, which may compromise stability.

Abstract: A differential microphone (50) produces a differential pair of output signals which are applied by a differential analogue amplifier (52). The amplified differential signals are converted to 1-bit form by a pair of analogue to digital converters (54, 55) and are combined in a 1-bit Delta Sigma Modulator.

Abstract: An array of user-operable controls and a proximity sensing apparatus are contained in an apparatus wherein the proximity sensing apparatus detects whether a user's hand is within a predetermined distance from the controls. Once the user's hand is a predetermined distance from the controls, a display screen displays screen icons associated with its respective control. The screen icons are controlled by a display processor which responsive to the user's hand being within a predetermined distance from the controls, alters the screen icon associated with its respective control.

Abstract: A digital audio signal processor processes digital audio signals having a first sampling rate S1. The processor has a multiplicity of manually adjustable controls (403) for setting desired parameters of signals to be processed. Sampling means (404) sample each control (403) setting at a second sampling rate S2 less than the first rate S1 to determine the settings thereof. Applying means (401) responsive to the sampling means apply the sampled settings to the signals. For each control the applying means determines the difference of successive samples of setting and applies to the signal, subject to control by that control, increments of setting each increment being a predetermined fraction 1/n of the said difference at a rate nS2 which is n times the said second sampling rate S2.

Abstract: A microphone comprises a housing; an acoustic-to-electrical signal transducer disposed within the housing, the transducer being operable to generate an analogue audio signal; and a one-bit analogue-to-digital converter disposed within the housing for converting the analogue audio signal into a one-bit digital audio signal for transmission to other, external, audio processing apparatus.

Abstract: A signal processor for 1-bit signals comprises a fifth order Delta-Sigma Modulator (DSM) having an input 4 for receiving a 1-bit signal and an output 5 at which a processed 1-bit signal is produced by a quantizer Q. The quantizer Q receives a p-bit signal from a series of 5 signal integration stages. Each stage comprises a first 1-bit multiplier An coupled to the input 4, a second 1-bit multiplier Cn coupled to the output 5, an adder 6n which sums the outputs of the coefficient multipliers and an integrator 7n which integrates the output of the adder 6n. A final stage comprises a coefficient multiplier An+1 and an adder 6n+1. The adder 6n+1 sums the output of the coefficient multiplier An+1 and the output of the integrator of the preceding integration stage.

Abstract: Data processing apparatus comprises an array of user-operable controls; proximity sensing apparatus associated with the controls for detecting whether a user's hand is within a predetermined distance of one or more of the controls; a display screen for displaying respective screen icons associated with the controls; and a display processor, responsive to a detection that a user's hand is within the predetermined distance of one of the controls, for altering the screen icon associated with that control.

Abstract: An audio signal processor for processing 1-bit signals, comprises an input 40 for receiving a 1-bit signal, means 41, 42 for applying a predetermined filter characteristic to the 1-bit signal whereby the signal is also converted to an n-bit signal where n is greater than one, means 43 for determining the absolute value of the n-bit signal, means 46, 51 for producing a dynamics control signal dependent on the said absolute value, means 48 for applying the dynamics control signal to the 1-bit input signal, and means 49 for requantizing the dynamics controlled signal as a 1-bit signal and shaping the noise in the requantized 1-bit signal. Circuits for producing LOG base 2 and the corresponding anti-log are also disclosed.

Abstract: Audio processing apparatus comprises an audio processor operable to apply audio processing operations to two or more input audio channels; user-operable adjustment controls for adjusting processing parameters associated with the audio processing operations; a display screen for displaying icons representing audio processing operations for each of the input audio channels, the display color of at least a part of an icon being defined by a logical color index; a data array mapping a set of logical color indices to colors for display on the display screen; and a detector for detecting user operation of the adjustment controls associated with an input audio channel and, in response to such a detection, for changing the display color of at least the part of the icon associated with that channel by changing the display color defined in the data array for the corresponding logical color index.

Abstract: Apparatus for storing or transmitting a one-bit digital signal comprises an input inverter for inverting a subset of the data bits of an input one-bit digital signal, to generate a bit-inverted signal; a storage or transmission medium for storing or transmitting the bit-inverted signal; and an output inverter for inverting the subset of the data bits of the bit-inverted signal, to regenerate the input one-bit digital signal.

Abstract: Data processing apparatus comprises an array of user-operable controls, the controls being adjustable by movement of a user's hand while touching a control; a detector for detecting when a user's hand is touching a control; a display screen for displaying respective screen icons associated with the controls; and a display processor, responsive to a detection that a user's hand is touching one of the controls, for altering the screen icon associated with that control.