Harmonic Source Enhancement Using Time-Frequency Audio Masking

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Solution Overview

Problem

Existing audio processing technologies struggle to effectively separate and enhance harmonic sources from audio signals, which is crucial for improved audio identification, authentication, and media classification.

Innovation Solution

The development of an audio analyzer and determiner system that processes audio signals to enhance harmonic sources by decomposing them into harmonic and percussive components, using techniques such as magnitude spectrogram analysis and time-frequency masking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If audio signals are processed to separate harmonic and percussive components, then audio identification accuracy is improved, but processing complexity increases

Engineering Contradiction:
Improveaudio identification accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The audio signal is segmented into harmonic and percussive components using spectral decomposition. The magnitude spectrogram is divided into harmonic regions (repeating patterns) and percussive regions (transient events), allowing separate processing and enhancement of each component to improve identification accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A time-frequency mask is introduced as an intermediary tool to selectively enhance harmonic components while suppressing percussive components. The mask is generated by analyzing the spectrogram and applying thresholding operations to create a binary mask that guides the enhancement process.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If harmonic sources are enhanced by separating from percussive components, then audio fingerprinting precision is improved, but computational requirements increase

Engineering Contradiction:
Improveaudio fingerprinting precisionVSAvoidcomputational requirements
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

Instead of processing the entire audio signal uniformly, the method applies partial action by focusing computational resources only on regions identified as harmonic through spectral analysis. The time-frequency mask selectively processes only the harmonic portions of the signal, reducing overall computational requirements while maintaining fingerprinting precision.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The spectrogram is pre-processed and analyzed to identify harmonic regions before the main enhancement operation. This preliminary action allows the system to prepare a time-frequency mask in advance, which then guides the enhancement process and reduces the computational burden during actual fingerprinting.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If audio signals are decomposed into harmonic and percussive components, then media classification accuracy is improved, but processing time increases

Engineering Contradiction:
Improvemedia classification accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The method leverages the periodic nature of harmonic sounds (musical tones, vowels) to identify and enhance them. By detecting the periodic repetitions in the spectrogram, the system can quickly distinguish harmonic from percussive components without requiring extensive processing, as the periodic pattern provides a clear temporal signature.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent replaces complex mechanical signal processing with spectral domain analysis. By transforming the audio signal into the frequency domain using Fast Fourier Transform (FFT), the system can efficiently separate harmonic and percussive components through spectral characteristics rather than time-domain convolution, reducing processing time.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS12236931B2Methods and apparatus for harmonic source enhancement
Publication Date: 2025.02.25 GRACENOTE INC
  • US12236931B2 patent drawing
  • US12236931B2 patent drawing
  • US12236931B2 patent drawing

AI summary

Methods and apparatus for harmonic source enhancement are disclosed herein. An example apparatus includes an interface to receive a media signal. The example apparatus also includes a harmonic source enhancer to determine a magnitude spectrogram of audio corresponding to the media signal; generate a time-frequency mask based on the magnitude spectrogram; and apply the time-frequency mask to the magnitude spectrogram to enhance a harmonic source of the media signal.