Mobile Speaker Switching with Receiver Equalization for Hands-Free Audio
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Solution Overview
Problem
Current mobile devices face limitations in switching between handset and hands-free modes due to the inherent design differences between receiver and hands-free speakers, resulting in inferior far-field reproduction and increased costs, power consumption, and material usage when employing two hands-free speakers.
Innovation Solution
A mobile device configuration that includes a high pass filter and receiver equalization filter in a cascade to match the frequency response of the receiver speaker to the hands-free speaker, along with a spatial sound processor and gain aligner, allowing for efficient switching between modes while optimizing speaker performance and reducing material and power requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a receiver speaker is used in hands-free mode, then the device can operate in both modes with a single speaker, but the far-field reproduction quality is inferior
Solution Approach 1:
The patent applies parameter changes by modifying the electrical characteristics of the receiver speaker through equalization filters and high-pass filters. These filters adjust the frequency response and impedance parameters to optimize the speaker's performance for far-field hands-free reproduction, transforming it from a near-field optimized device to one that can also handle far-field conditions effectively.
2Manufacturing precision
If two hands-free speakers are used, then the sound pressure level and stereo imaging are improved, but the cost, space, and power consumption increase
Solution Approach 1:
The patent implements universality by enabling the receiver speaker to perform multiple functions: near-field handset mode and far-field hands-free mode. Through the use of equalization filters and high-pass filters, the single speaker is transformed into a multi-functional component that can adapt to different acoustic requirements, eliminating the need for separate hands-free speakers while maintaining spatial sound quality.
Solution Approach 2:
The patent uses parameter changes to transform the receiver speaker's characteristics to suit hands-free operation. By adjusting frequency response through equalization and applying high-pass filtering, the speaker's acoustic output is modified to achieve broad spatial sound image and acceptable far-field reproduction, allowing one speaker to replace what would traditionally require two hands-free speakers.
3Power
If the receiver speaker is driven with high power in hands-free mode, then the acoustic output is improved, but the speaker may be damaged due to mechanical and thermal limits
Solution Approach 1:
The patent applies parameter changes by using high-pass filters to modify the frequency content of the audio signal. By removing low-frequency components that cause excessive mechanical excursion and thermal loading, the speaker can operate at higher overall power levels in hands-free mode without exceeding its mechanical and thermal limits, thus improving acoustic output while maintaining reliability.
Data Source
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AI summary
Mobile devices such as mobile phones typically have two speakers, one for use in a hand-set mode and one for use in a hands-free mode. A mobile device (1100) is described operable to switch between a hand-set mode and a hands-free mode, the mobile device includes a receiver speaker (10) operable in the hand-set mode and the hands-free mode of the mobile device, and a hands-free speaker (12) operable in the hands-free mode of the mobile device. The mobile device is operable in hands-free mode to route at least one audio signal to the receiver speaker and the hands-free speaker. Using the hands-free speaker and the receiver speaker may improve the sound quality without increasing the cost.