Audio Playback SPL Control for Perceptual Power Reduction
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Solution Overview
Problem
Existing audio playback systems face challenges in reducing power consumption while maintaining audio quality, as techniques like audio masking alone do not result in significant power savings and can introduce audible sound pressure level reductions.
Innovation Solution
A system and method that utilize psychoacoustic principles, specifically auditory masking and speaker sound pressure level response, to attenuate signal components at frequencies not producing a perceptible auditory response, using a controller to compare the sound pressure level response of a first frequency band to the total sound pressure level response and attenuate components when the ratio falls below a threshold, thereby reducing power consumption without affecting the listening experience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If audio masking is used to attenuate frequencies, then power consumption is reduced, but audible sound pressure level reductions occur
Solution Approach 1:
The system dynamically changes signal processing parameters by comparing the SPL response of a first frequency band to the total SPL response. When the ratio falls below a threshold, the controller attenuates components in the first frequency band, thereby reducing power consumption while maintaining perceived audio quality through psychoacoustic masking principles
Solution Approach 2:
The controller acts as an intermediary that processes the audio signal by comparing SPL responses across different frequency bands and selectively attenuating components based on the ratio comparison, thereby mediating between power reduction goals and audio quality maintenance
2Use of energy by moving object
If signal components at low frequencies are attenuated, then power consumption is reduced significantly, but the audio output may become perceptibly degraded
Solution Approach 1:
The system monitors the ratio of SPL response of low-frequency components to total SPL response and dynamically adjusts attenuation levels based on this ratio comparison, reducing power consumption when low-frequency content is minimal while preserving audio quality when low-frequency content is significant
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 achieves power savings of up to 10% or more without negatively impacting the user's listening experience by attenuating low-frequency components that are masked or inaudible, and up to 5% by reducing high-frequency components, while preserving the audio quality.
Implementation Method 1
The principle of audio masking can be leveraged to reduce power consumption in an audio playback system. For example, audio signals at frequencies that are masked by other frequencies may be attenuated to reduce overall power consumption.
Implementation Method 2
The controller is configured to compare a SPL response of a first frequency band of the signal to a total SPL response of the signal
Data Source
AI summary
A method of reducing power consumed by an audio playback system includes: receiving a signal from a digital audio interface; comparing a sound pressure level (SPL) response of a first frequency band of the signal to a total SPL response of the signal, the first frequency band including frequencies lower than a selected frequency; and attenuating signal components in the first frequency band of the signal based upon the comparison of the SPL response of the first frequency band of the signal to the total SPL response of the signal.