Speaker Loudness Control Using Selective Band Boosting
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Solution Overview
Problem
Existing device speaker systems face challenges in enhancing far-end speech signal loudness in noisy environments without damaging the speaker hardware, often resulting in decreased intelligibility and increased size and power consumption due to redundant hardware.
Innovation Solution
A noise-level analyzer and intelligent speaker-boosting logic system that selectively boosts specific frequency bands of the far-end speech signal, monitoring speaker activity and power levels to optimize loudness without exceeding safe excursion limits, using a class-D amplifier to drive the speaker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the loudness of the far-end speech signal is enhanced to overcome near-end noise, then the audibility of the speech signal is improved, but the speaker membrane excursion and voice coil temperature increase causing potential speaker damage
Solution Approach 1:
The patent applies different gain levels to different frequency bands of the speech signal. The system identifies which frequency bands are most affected by near-end noise and applies targeted boosting only to those bands, rather than uniformly boosting all frequencies. This localized approach enhances speech audibility in noisy frequencies while minimizing overall speaker excursion and heat generation.
Solution Approach 2:
The system dynamically adjusts the gain parameter for specific frequency bands based on real-time analysis of near-end noise levels and speaker operating conditions. By changing the amplification parameter selectively across different frequency ranges, the system optimizes speech intelligibility while keeping speaker membrane excursion and voice coil temperature within safe limits.
2Illumination intensity
If the far-end speech signal is boosted to maximum levels to ensure intelligibility, then the speech becomes audible over noise, but the intelligibility of the boosted speech signal decreases
Solution Approach 1:
The patent preserves speech intelligibility by applying gain enhancement selectively only to frequency bands that are masked by near-end noise. Frequency bands that already contain clear speech information are left unboosted, preventing the degradation of speech quality and intelligibility while still improving overall audibility in noisy conditions.
Solution Approach 2:
The system applies partial boosting - only enough gain to overcome the masking effect of near-end noise in affected frequency bands, rather than excessive boosting across all frequencies. This partial action approach maintains speech intelligibility by avoiding over-amplification that would distort the speech signal.
3Object-affected harmful factors
If speaker-boost protection systems are used to enhance acoustical output while limiting speaker excursion, then speaker damage is prevented, but redundant hardware is required increasing size and power consumption
Solution Approach 1:
The patent integrates speaker protection functionality into the existing signal processing chain by using the same frequency analysis and gain control mechanisms that are already present for noise compensation. The system performs dual functions - both enhancing speech intelligibility and protecting the speaker - using the same processing resources, thereby eliminating the need for separate redundant hardware protection circuits.
Solution Approach 2:
The system combines the speech enhancement algorithm with speaker protection logic into a unified processing framework. By merging these two functions into a single integrated system that shares common components for frequency analysis, gain control, and signal processing, the patent reduces hardware redundancy while achieving both speech intelligibility improvement and speaker protection.
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 enhances far-end speech signal audibility in noisy environments while preventing speaker damage, maintaining intelligibility and reducing power consumption by applying targeted signal boosting based on environmental noise and speaker characteristics.
Implementation Method 1
using a class-D amplifier to drive the speaker
Data Source
AI summary
A mechanism to adjust far-end signal loudness based on environmental noise levels and device speaker characteristics has a noise-level analyzer that receives feedback from an intelligent speaker-boosting logic circuit that provides a signal to a class-D amplifier to drive the speaker. The noise-level analyzer analyzes near-end environmental noise levels and far-end speech input signal levels across critical frequency bands. The noise-level analyzer performs a masking analysis of the far-end and near-end signals, and guides the speaker-boosting logic circuit to apply determined signal boosting levels over selective bands. The speaker-boosting logic circuit monitors system activity along with the selective band boosting guidance from the noise-level analyzer. Using device speaker information and the speaker excursion pattern, the speaker-boosting logic circuit adjusts far-end speech signal loudness without over excursion of the speaker and damage to the speaker hardware.