Ratio-Based Audio Attenuation for Speech-Over-Music Intelligibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Personal listening devices, such as headphones and earbuds, create a good acoustic seal that reduces the ability to hear important environmental sounds, like alerts, due to their design for high-quality audio, which can make alert signals inaudible if the entertainment signal is too loud.
Innovation Solution
An audio processing system with a voice activity detector and a ratio-based attenuator that intelligently adjusts the entertainment signal level to maintain a constant voice-to-music ratio, ensuring alert signals from the environment are audible while suppressing other environmental sounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the entertainment signal level is increased to provide high-quality audio, then the audio quality is improved, but the alert signal becomes inaudible
Solution Approach 1:
The system dynamically adjusts the entertainment signal level based on the detected alert signal characteristics. The voice activity detector continuously monitors environmental sounds, and when speech or alert signals are detected, the system automatically reduces the entertainment signal level to ensure intelligibility, then restores it when the alert signal ceases.
Solution Approach 2:
The system employs a feedback mechanism where the voice activity detector monitors environmental sounds and provides control signals to the ratio-based attenuator. This closed-loop system continuously compares the alert signal level with the entertainment signal level and adjusts the attenuation ratio accordingly to maintain optimal intelligibility while preserving audio quality.
2Loss of information
If the entertainment signal level is decreased to make alert signals audible, then the alert signal intelligibility is improved, but the entertainment signal quality deteriorates
Solution Approach 1:
The system applies partial attenuation to the entertainment signal only when and to the extent necessary for alert signal intelligibility. The ratio-based attenuator calculates the precise attenuation level needed based on the voice-to-music ratio, avoiding excessive suppression of entertainment content while ensuring alert signals remain intelligible.
3Loss of information
If environmental sound is mixed with entertainment signal to improve alert signal detection, then the alert signal intelligibility is improved, but unnecessary environmental sounds are also heard
Solution Approach 1:
The system extracts only the relevant alert signal components from environmental sounds using the voice activity detector. This detector identifies speech and alert signals through voice activity detection algorithms, separating them from other environmental noises. The system then selectively attenuates the entertainment signal based on these extracted alert signals without mixing in unnecessary environmental sounds.
Data Source
AI summary
An audio processing system for a listening device includes an input device, a voice activity detector and a ratio-based attenuator. The input device is configured to receive a first audio signal emanating from an environment and including a signal of interest. The voice activity detector is configured to generate a control signal in response to the first audio signal. The ratio-based attenuator is configured to receive the control signal and determine whether the signal level of the first audio signal exceeds the signal level of an audio signal received from an audio playback device by at least a target difference. If so, then the audio level of the playback audio signal is maintained. Otherwise, the audio level of the playback audio signal is adjusted, where, at the adjusted value, the first signal level exceeds the playback signal level by at least the target difference.