An audio field adjusting method can be applied to a stereo system having a plurality of sound boxes, and each of the plurality of sound boxes includes an Ultra-Wide Band (UWB) module. The method can include: obtaining a user position fed back by the UWB module in each of the plurality of the sound boxes; determining an audio field center position according to the user position fed back by the UWB module in each of the plurality of the sound boxes; and according to the audio field center position, adjusting an audio field position of each of the plurality of the sound boxes, such that an audio field position of the stereo system is the audio field center position.

A device for processing audio signals, including: first and second input units providing first and second input signals of first and second audio tracks, a decomposition unit to decompose the first input audio signal to obtain a plurality of decomposed signals, a playback unit configured to start playback of a first output signal obtained from recombining at least a first decomposed signal at a first volume level with a second decomposed signal at a second volume level, such that the first output signal substantially equals the first input signal, and a transition unit for performing a transition between playback of the first output signal and playback of a second output signal obtained from the second input signal. The transition unit has a volume control section adapted for reducing the first and second volume levels according to first and second transition functions.

Examples described herein relate to management of concurrent audio streams from different sources. Portable playback devices, such as wearable wireless headphones and earbuds, as well as portable battery-powered speakers, may include multiple network interfaces for connection to different types of networks, such as an 802.11-compatible network interface for connection to wireless local area networks (e.g., Wi-Fi networks) and an 802.15-compatible network interface for connection to a mobile device via a personal area network (Bluetooth). Via such connections, the playback devices may receive two or more concurrent streams. By managing these streams according to playback policies, the portable playback devices may play the user's intended audio without necessarily requiring user input to explicitly select among the concurrent streams.

A wireless receiver (10) includes a down converter module (210) operable to deliver a signal having a signal bandwidth that changes over time, a dynamically controllable filter module (200) having a filter bandwidth and fed by said down converter module (210), and a measurement module (295) operable to at least approximately measure the signal bandwidth, said dynamically controllable filter module (200) responsive to said measurement module (295) to dynamically adjust the filter bandwidth to more nearly match the signal bandwidth as it changes over time, whereby output from said filter module (200) is noise-reduced. Other wireless receivers, electronic circuits, and processes for their operation are disclosed.

A demodulation apparatus according to the present disclosure includes an analog audio demodulator, a digital audio demodulator, a selection circuit, and a noise addition circuit. The analog audio demodulator demodulates a received signal of an analog radio broadcast wave into an analog audio signal and outputs the analog audio signal. The digital audio demodulator demodulates a received signal of a digital radio broadcast wave into a digital audio signal and outputs the digital audio signal, the analog/digital radio broadcast waves including audio signals indicative of a same content and being broadcasted simultaneously. The selection circuit selects either the analog audio signal or the digital audio signal. The noise addition circuit adds noise to the digital audio signal in a first period including a switching period for switching from a state where the analog audio signal is selected to a state where the digital audio signal is selected.

Disclosed is a digital stereo multiplexing-demultiplexing system based on the use of delta-sigma modulation. Creation of left (LR) and right (L+R) channels is achieved using a binary delta adder IC circuit. Delta adder is an ordinary binary adder with an interchanged role of the Sum and Carry-Out terminals. Two channel multiplexer and demultiplexer are implemented with ordinary binary logic gates. Output of the multiplexer is modulated and transmitted to the receiver where demultiplexing is performed. The proposed method can combine two or more digital stereo channels. This method is not application limited, and can be used in acoustic, video, or photo applications.

A demodulation apparatus according to the present disclosure includes an analog audio demodulator, a digital audio demodulator, a selection circuit, and a noise addition circuit. The analog audio demodulator demodulates a received signal of an analog radio broadcast wave into an analog audio signal and outputs the analog audio signal. The digital audio demodulator demodulates a received signal of a digital radio broadcast wave into a digital audio signal and outputs the digital audio signal, the analog/digital radio broadcast waves including audio signals indicative of a same content and being broadcasted simultaneously. The selection circuit selects either the analog audio signal or the digital audio signal. The noise addition circuit adds noise to the digital audio signal in a first period including a switching period for switching from a state where the analog audio signal is selected to a state where the digital audio signal is selected.

Examples described herein relate to management of concurrent audio streams from different sources. Portable playback devices, such as wearable wireless headphones and earbuds, as well as portable battery-powered speakers, may include multiple network interfaces for connection to different types of networks, such as an 802.11-compatible network interface for connection to wireless local area networks (e.g., Wi-Fi? networks) and an 802.15-compatible network interface for connection to a mobile device via a personal area network (Bluetooth?). Via such connections, the playback devices may receive two or more concurrent streams. By managing these streams according to playback policies, the portable playback devices may play the user's intended audio without necessarily requiring user input to explicitly select among the concurrent streams.

The present disclosure provides a method and a dual band receiver for handling an analog dual band radio signal comprising a first frequency band component and a second frequency band component. The method comprises sampling the analog dual band radio signal through the use of interleaving analog-to-digital converters, ADCs, to obtain four sampled signals including a first I component, Iin+, a first Q component, Qin+, a second I component, Iin, and a second Q component, Qin, wherein phases of Qin+, Iin and Qin are respectively offset with respect to phases of Iin+, Qin+ and Iin by /2. Then, the four sampled signals are filtered through the use of polyphase filters to obtain a first set of filtered signals (a1, a2, a3, a4) each of which has a same power as the first frequency band component and a second set of filtered signals (b1, b2, b3, b4) each of which has a same power as the second frequency band component. Subsequently, a power of the first frequency band component, a power of the second frequency band component and a total power of the first frequency band component and the second frequency band component are estimated, based on the four sampled signals, the first set of filtered signals and the second set of filtered signals. Next, the first frequency band component and the second frequency band component are selectively attenuated based on the estimated powers.

A wireless receiver includes a down converter module operable to deliver a signal having a signal bandwidth that changes over time, a dynamically controllable filter module having a filter bandwidth and fed by said down converter module, and a measurement module operable to at least approximately measure the signal bandwidth, said dynamically controllable filter module responsive to said measurement module to dynamically adjust the filter bandwidth to more nearly match the signal bandwidth as it changes over time, whereby output from said filter module is noise-reduced. Other wireless receivers, electronic circuits, and processes for their operation are disclosed.