Pitch Estimation Using Spectral Basis Vectors and Temporal Constraints

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Solution Overview

Problem

Current computerized systems lack the ability to effectively detect and transcribe musical sources within a sound mixture, as they are not as developed as human ear training in associating sounds with specific instruments and notes.

Innovation Solution

A method for estimating features of a sound mixture using a model with a dictionary of spectral basis vectors, where the model is based on isolated training data and includes feature tagging, allowing for pitch estimation constrained by temporal data, such as a semantic continuity constraint.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If computerized systems use basic spectral analysis to detect sound sources, then the system complexity remains low, but the measurement precision of pitch and volume estimation is insufficient

Engineering Contradiction:
Improvepitch estimation accuracyVSAvoidmodel complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary training to pre-compute spectral basis vectors and construct dictionaries for each sound source type before actual pitch estimation. This pre-processing creates reusable models that improve measurement precision without increasing real-time computational complexity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The pitch estimation process is segmented into distinct phases: spectral decomposition using pre-computed basis vectors, dictionary matching for source identification, and temporal constraint application. This segmentation allows complex operations to be performed offline while keeping online processing manageable

Inventive Principle:
Principle #1Segmentation

2Reliability

If the system estimates features for each time frame independently, then the processing speed is fast, but the reliability of pitch tracking is poor due to temporal inconsistencies

Engineering Contradiction:
Improvepitch tracking consistencyVSAvoidprocessing speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system applies temporal constraints that use feedback from previous time frame estimates to constrain current estimates. The semantic continuity constraint ensures that pitch estimates evolve smoothly over time, preventing unrealistic jumps and improving tracking reliability

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The pitch estimation maintains continuity by applying temporal constraints that enforce smooth transitions between successive time frames. This ensures that the pitch tracking remains reliable while processing occurs efficiently at each time step

Inventive Principle:
Principle #20Continuity of useful action

3Adaptability or versatility

If the system uses isolated training data to build source models, then the adaptability to different instruments is improved, but the loss of information occurs when sources are mixed together

Engineering Contradiction:
Improveinstrument recognition capabilityVSAvoidspectral information loss in mixture
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The system transforms the sound mixture analysis into a different dimensional space using spectral decomposition. By representing sounds in terms of spectral basis vectors and matching them against dictionaries of normalized spectra, the system recovers information that would be lost in the time domain mixture

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The spectral basis vectors serve as intermediaries between the mixed sound signal and the source identification process. These basis vectors capture the essential spectral characteristics of each source type, enabling the system to separate and identify individual sources even when they are mixed together

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS8965832B2Feature estimation in sound sources
Publication Date: 2015.02.24 ADOBE INC
  • US8965832B2 patent drawing
  • US8965832B2 patent drawing
  • US8965832B2 patent drawing

AI summary

A sound mixture may be received that includes a plurality of sources. A model may be received for one of the source that includes a dictionary of spectral basis vectors corresponding to that one source. At least one feature of the one source in the sound mixture may be estimated based on the model. In some examples, the estimation may be constrained according to temporal data.