Hearing Protection Audio Control Using Loudness-Level Adjustment
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Solution Overview
Problem
Current automatic volume control methods for headphones adjust sound pressure levels across frequency bands but do not accurately represent the user's hearing experience, failing to effectively protect hearing.
Innovation Solution
A sound adjustment method and device that convert original sound pressure levels to loudness levels, adjust these levels based on preset values, and then convert back to adjusted sound pressure levels to produce an adjusted sound signal, ensuring hearing protection by reducing volume when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If automatic volume control adjusts sound pressure level values directly, then the control process is simple, but the adjustment does not accurately represent the user's hearing experience
Solution Approach 1:
The patent introduces loudness level values as an intermediary parameter between sound pressure level values and user hearing experience. The adjustment process uses loudness level values to mediate the relationship, converting sound pressure level measurements into perceptually relevant loudness levels, then using these as the basis for volume control adjustments. This intermediary approach resolves the contradiction by maintaining measurement precision through objective loudness level calculations while achieving accurate hearing experience representation.
2Adaptability or versatility
If sound pressure level values are used for volume control, then the control method is straightforward, but it does not meet the actual hearing situation of users
Solution Approach 1:
The patent changes the parameter basis for volume control from sound pressure level values to loudness level values. This parameter transformation enables the system to adapt to actual hearing situations by using loudness levels, which account for frequency-dependent human ear sensitivity. The control method remains relatively simple as it still involves automatic adjustment, but the parameter change fundamentally improves adaptability to human hearing characteristics.
3Reliability
If direct sound pressure level adjustment is performed, then the processing time is short, but the hearing protection effect is insufficient
Solution Approach 1:
The patent performs preliminary conversion of sound pressure level values to loudness level values before executing the volume control adjustment. This preliminary action ensures that the subsequent adjustment is based on perceptually accurate loudness levels, thereby improving hearing protection effectiveness. The preprocessing step of converting to loudness levels occurs automatically and quickly, minimizing the time loss while ensuring reliable hearing protection through accurate perceptual measurement.
Data Source
AI summary
A sound adjustment method includes the following steps: obtaining a sound signal including frequency bands with a corresponding original sound pressure level value; converting the original sound pressure level value of each frequency band into a corresponding loudness level value; adjusting each loudness level value by a preset loudness level value to obtain an adjusted loudness level value of each frequency band; converting each adjusted loudness level value into a corresponding adjusted sound pressure level value; calculating a target sound pressure level value of each frequency band according to the original sound pressure level of each frequency band and each adjusted sound pressure level value; adjusting the original sound pressure level value of each frequency band by each target sound pressure level value to obtain an adjusted sound signal; outputting the adjusted sound signal.