Dynamic Audio Normalization Using Multi-Band Compression

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Solution Overview

Problem

Existing video content distribution methods, particularly those using broadcast networks or IP-based networks, often result in sudden volume changes, which can be unpleasant for individuals with PTSD, hearing aids users, and those with autism, as dynamic ad insertion techniques frequently cause advertisements to be significantly louder than the content, leading to unpleasant viewing experiences that conventional manual adjustments and audio processing techniques fail to address effectively.

Innovation Solution

A system that dynamically normalizes and compresses audio in video streams by splitting audio into multiple bands based on decibel levels, determining acceptable audio ranges using national hearing data and other standards, and generating a second audio track that maintains the integrity of the audio while reducing loud noises and enhancing quiet portions, which can be selected by users during playback without requiring end-user processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If dynamic ad insertion techniques are used to insert advertisements into video content, then advertising revenue and content variety are improved, but audio volume becomes significantly louder than the rest of the content, causing unpleasant viewing experiences

Engineering Contradiction:
Improvecontent varietyVSAvoidaudio volume discrepancy
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The system applies dynamic audio processing that adjusts compression and normalization parameters in real-time based on the detected audio characteristics of each segment. The processor continuously monitors audio levels and adapts the processing intensity to match the content type, allowing advertisements and program content to be delivered at consistent perceived volumes despite their inherently different audio profiles.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes audio processing parameters dynamically based on content analysis. It detects whether a segment is an advertisement or program content and adjusts normalization targets, compression ratios, and limiting thresholds accordingly. This allows the system to compensate for the typically higher volume characteristics of advertisements while maintaining the integrity of program content audio levels.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conventional audio processing techniques are used to normalize audio levels, then overall audio consistency is improved, but all sounds are enhanced uniformly, causing quiet audio portions to be reduced to inaudible levels or causing clipping

Engineering Contradiction:
Improveaudio consistencyVSAvoidaudio level control
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The system segments the audio spectrum into multiple frequency bands and processes each band independently with tailored compression and normalization parameters. This prevents uniform processing from either clipping loud sounds or making quiet sounds inaudible, as each frequency range receives appropriate attention based on its specific characteristics and the overall audio balance requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies different processing qualities to different portions of the audio signal. Rather than uniform normalization, it identifies specific audio segments that require attention and applies targeted processing only where needed, preserving the natural dynamic range in areas that don't require intervention while correcting problematic sections.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If manual volume adjustment is used to compensate for loud advertisements, then individual user control is improved, but the solution is impractical for continuous viewing and does not address the root cause

Engineering Contradiction:
Improveuser controlVSAvoidcontinuous adjustment time
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The system performs automatic audio level normalization and compression without requiring user intervention. The processor continuously monitors and adjusts audio levels in real-time, compensating for loud advertisements and sudden volume changes automatically, freeing users from the need to manually adjust volume controls during viewing.

Inventive Principle:
Principle #25Self-service

4Object-affected harmful factors

If conventional compression techniques are used to reduce audio dynamic range, then loud sounds are reduced, but clipping occurs and quiet audio portions are reduced to inaudible levels

Engineering Contradiction:
Improveloud sound reductionVSAvoidaudio quality
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The system employs dynamic compression with continuously variable parameters that adapt to the instantaneous audio signal characteristics. The compression ratio, attack time, and release time are adjusted in real-time based on the detected audio levels and content type, preventing both clipping of loud sounds and excessive reduction of quiet portions that would occur with fixed-ratio compression.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback mechanisms where the output of the compression process is continuously monitored and fed back to adjust the compression parameters. This closed-loop control prevents clipping by detecting when compression is approaching problematic levels and automatically reducing the compression ratio, while simultaneously ensuring quiet portions remain audible by adjusting the overall gain structure based on the compressed signal characteristics.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS11558022B2Dynamic audio normalization process
Publication Date: 2023.01.17 COMCAST CABLE COMM LLC
  • US11558022B2 patent drawing
  • US11558022B2 patent drawing
  • US11558022B2 patent drawing

AI summary

Methods, systems, and apparatuses are described herein for improved processing audio in a video stream. A system may split audio in a frame of video content into multiple bands based on their audio levels. The system may then dynamically compress and dynamically normalize the audio level in each band. When dynamically compressing the bands, the system may determine, based on stored information, what audio level range is acceptable for an end user and may smooth and maintain the ranges of the audio to be within the acceptable range. The system may include the dynamically normalized and dynamically compressed frames as a second audio track in the video content. A computing device receiving the video content may select the second audio track during playback. If an end user selects the second audio track, the video is delivered with the modified sound of the second audio track.