Speaker Device Sound Beam Virtual Source Localization
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Solution Overview
Problem
Existing speaker apparatuses face challenges in distinctly localizing sound sources, especially in environments with low acoustic reflectivity or when the listener is not near a wall, and struggle to maintain localization feeling when using virtual sound sources or sound beams alone, leading to indistinctive localization and impaired surround sound effects.
Innovation Solution
The proposed speaker apparatus employs a combination of sound beams and virtual sound sources, utilizing head-related transfer functions and adaptive gain adjustments to enhance localization, while ensuring that the frequency characteristics of the initial reflected sound do not interfere with the virtual sound source perception, thereby maintaining a strong localization feeling across different listening environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sound beam alone is used for localization, then directivity and spatial positioning are improved, but localization feeling is weakened in environments with low acoustic reflectivity or when listener is not near a wall
Solution Approach 1:
The patent combines sound beam technology with virtual sound source technology by superimposing the sound beam signal with a virtual sound source signal generated through head-related transfer function processing. This merging allows the system to maintain directivity benefits while compensating for localization feeling degradation in environments without reflective surfaces or when the listener is远离 walls.
Solution Approach 2:
The head-related transfer function acts as an intermediary that converts the sound beam signal into a virtual sound source signal. This intermediary processing adds the necessary frequency characteristics and spatial cues that create the perception of a virtual sound source, thereby enhancing localization feeling while maintaining the directivity advantages of sound beams.
2Measurement precision
If virtual sound source alone is used for localization, then frequency characteristic modification is achieved, but localization feeling is impaired and surround sound effect is degraded
Solution Approach 1:
The patent merges virtual sound source signals with sound beam signals to create a composite output. The virtual sound source component provides frequency characteristic modification through head-related transfer function, while the sound beam component maintains strong localization feeling and surround sound effect. This combination resolves the impairment of localization feeling that occurs when virtual sound sources are used alone.
3Reliability
If sound beam and virtual sound source are combined, then localization feeling is enhanced, but frequency characteristic interference from initial reflected sound may occur
Solution Approach 1:
The patent extracts and separates the initial reflected sound component from the overall sound field. By identifying and isolating this component, the system can prevent it from interfering with the frequency characteristics of the virtual sound source signal. This extraction allows the combined sound beam and virtual sound source signals to maintain their intended frequency characteristics without contamination from unwanted reflections.
Solution Approach 2:
The patent converts the potentially harmful initial reflected sound into a beneficial element by using it to identify and characterize the acoustic environment. This reflected sound information is utilized to adjust and optimize the virtual sound source signal generation, transforming what would be interference into a useful cue for enhancing localization accuracy and frequency characteristic control.
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 allows for distinct localization of sound sources in intended directions, even in challenging environments, and provides a stronger localization feeling than conventional methods using sound beams or virtual sound sources alone, while maintaining the surround sound effect without degrading the audio experience.
Implementation Method 1
filtering processing based on a head-related transfer function is carried out for performing processing for localizing a virtual sound source
Implementation Method 2
An array speaker apparatus outputting a sound beam having a directivity by delaying audio signals and distributing the delayed audio signals to a plurality of speaker units is conventionally known
Implementation Method 3
a sound source is localized by making a sound beam of each channel reflected on a wall to reach a listener from around the listener
Data Source
Figure 1
Figure 2
Figure 3(A)
AI summary
A speaker apparatus capable of distinctively localizing a sound source by employing localization based on a virtual sound source while taking advantages of the characteristic of a sound beam is provided. The speaker apparatus (2) includes: an input portion (11) to which audio signals of a plurality of channels are input; a plurality of speakers (21A to 21P, 33L and 33R); a directivity controlling portion (20) causing the plurality of speakers to output a plurality of sound beams by delaying the audio signals of the plurality of channels input to the input portion (11) and distributing the delayed signals to the plurality of speakers; and a localization adding portion (42) subjecting at least one of the audio signals of the plurality of channels input to the input portion (11) to filter processing based on a head-related transfer function and inputting the processed signal to the plurality of speakers.