Ultrasound-Based Audio Array Beamforming Adaptation
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Solution Overview
Problem
Conventional audio systems face challenges in accurately tracking user positions, especially during short bursts of acoustic activity, and are prone to false detections due to noise sources, requiring complex and resource-intensive video camera or infrared sensor solutions.
Innovation Solution
An audio system that uses ultrasound signals to adapt filter characteristics and weights for an audio band array, allowing for directional beam formation even without a sound source, and employs wideband sensors for both audio and ultrasound functions, reducing resource usage and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional acoustic beamforming is used to adapt weights based on audio sources, then the system can provide directional audio rendering, but the adaptation can only occur after a sound source becomes active and tends to become inaccurate during short bursts of acoustic activity
Solution Approach 1:
The system performs preliminary action by using ultrasound signals to estimate user position and pre-adapt the audio array weights before acoustic activity begins. This allows the beamforming weights to be ready in advance, eliminating the adaptation delay that occurs when waiting for sound sources to become active.
2Measurement precision
If conventional acoustic beamforming is used with weight adaptation algorithms, then directional audio rendering can be achieved, but false detections occur in the presence of other acoustic sources such as radios or computers
Solution Approach 1:
The system introduces an intermediary approach by using ultrasound signals as a separate, independent sensing modality that is not affected by audible sound sources. The ultrasound-based position estimation acts as a reliable mediator that prevents false detections from radios, computers, or other acoustic sources.
3Measurement precision
If video cameras are used to perform position determination and control weight adaptation, then position tracking can be achieved, but the system becomes complex, expensive and resource demanding
Solution Approach 1:
The system applies multi-functionality by using the audio array elements to perform both audio signal processing and ultrasound-based position estimation. This eliminates the need for separate video cameras or infrared sensors, reducing system complexity while maintaining position tracking capability.
4Adaptability or versatility
If beamforming is employed to track user positions, then directional audio effects can be provided, but user tracking becomes inaccurate during short bursts of acoustic activity typical for speech applications
Solution Approach 1:
The system uses ultrasound signals to perform preliminary position estimation and weight adaptation before speech bursts occur. This ensures that the beamforming weights are already optimized for the user's position, maintaining tracking accuracy even during short acoustic activity bursts where conventional methods would fail.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables faster and more accurate user position tracking, improved beamforming performance, and reduced interference from unwanted sound sources, while being cost-efficient and less complex.
Implementation Method 1
an ultrasound sensor array which comprises a plurality of ultrasound sensors and is arranged to generate a plurality of ultrasound signals
Implementation Method 2
acoustic beamforming is relatively common in many applications... weights are applied to the signals of individual audio elements thereby resulting in the generation of a beam pattern for the array
Data Source
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AI summary
An audio system comprises an ultrasound sensor array (105) which has a plurality of ultrasound sensor elements, and an audio band array (101) comprising a plurality of audio band elements. The same array of wideband audio transducers may be used for both the ultrasound sensor array (105) and the audio band array (101). An estimator (107) generates a presence characteristic of a user in response to ultrasound signals received from the ultrasound sensor array. The presence characteristic may specifically comprise a position estimate for the user. An audio array circuit (103) generates a directional response for the audio band array (101) by applying weights to individual audio band signals for the audio band elements. A weight circuit (109) determines the weights in response to the presence characteristic. The system may provide improved adaptation of the directivity of the audio band array (101) and specifically does not require the sound source in the audio band to be active for adaptation.