Automatic Call Screening With Audio Embeddings for Spoofed Numbers

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Solution Overview

Problem

Spam calls, particularly robocalls, are a significant problem due to the use of fake or spoofed numbers, which undermines the efficacy of number-based anti-spam tools, leading to user inconvenience and increased interaction with unwanted calls.

Innovation Solution

A computer-implemented method using a trained machine-learning model generates embeddings from audio recordings and metadata of calls, clusters similar calls, and automatically determines and mitigates spam calls on client devices without user intervention, utilizing local storage and processing to compare call embeddings with spam models.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If number-based anti-spam tools are used, then call filtering is simplified, but efficacy deteriorates due to fake or spoofed numbers

Engineering Contradiction:
Improvecall filtering simplicityVSAvoidspam detection efficacy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces number-based filtering (mechanical system) with voiceprint-based biometric authentication. Instead of comparing phone numbers, the system extracts and compares unique vocal characteristics from call audio, making the filtering mechanism immune to spoofed numbers while maintaining operational simplicity.

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

Solution Approach 2:

The patent changes the identification parameter from phone number (metadata) to voiceprint characteristics (audio features). By analyzing spectral features, pitch, timbre, and other vocal parameters, the system creates a reliable identifier that cannot be faked, directly resolving the efficacy problem while keeping the interface simple.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If all calls are manually reviewed, then spam detection accuracy is maximized, but user time and productivity deteriorate

Engineering Contradiction:
Improvespam detection accuracyVSAvoiduser time for call review
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements self-service spam detection where the system automatically performs voiceprint extraction, comparison, and call classification without user intervention. The automated system maintains high accuracy by using sophisticated audio analysis while eliminating the need for manual review, thus saving user time.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system incorporates feedback mechanisms where user responses to automatic classifications are used to refine and update voiceprint models continuously. This feedback loop maintains high detection accuracy over time while keeping the process automated, preventing the need for manual review.

Inventive Principle:
Principle #23Feedback

3Reliability

If voice-based authentication is implemented, then spam call identification improves, but device complexity increases

Engineering Contradiction:
Improvecall authentication accuracyVSAvoidprocessing system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the voice authentication process into distinct modules: audio recording, pre-processing, feature extraction, voiceprint generation, comparison, and decision-making. Each module handles a specific task, making the overall complex system manageable and maintainable while achieving high authentication reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces voiceprint templates as an intermediary representation between raw audio and authentication decisions. These pre-generated templates serve as a bridge, allowing complex audio analysis to be performed once during setup and then used for rapid, simpler comparisons during actual call authentication.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If user privacy is fully protected, then data security improves, but information availability for spam detection deteriorates

Engineering Contradiction:
Improvedata securityVSAvoidcall data availability
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent extracts only the essential voiceprint features from call audio while discarding all other personal information. By taking out only the necessary biometric data (spectral characteristics, pitch patterns) and leaving behind identifying information like phone numbers or personal details, the system maintains data security while preserving enough information for effective spam detection.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS20250323997A1Automatic call categorization and screening
Publication Date: 2025.10.16 GOOGLE LLC
  • US20250323997A1 patent drawing
  • US20250323997A1 patent drawing
  • US20250323997A1 patent drawing

AI summary

Implementations described herein relate to methods, systems, and computer-readable media to automatically answer a call. In some implementations, a method includes receiving a call from a caller device at a client device. The method further includes determining, based on an identifier associated with the call, whether the call matches auto answer criteria, and yin response to determining that the call matches the auto answer criteria, answering the call without user input and without alerting a user of the client device. The method further includes generating a call embedding for the call based on received audio of the call, comparing the call embedding with spam embeddings to determine whether the call is a spam call, and in response to determining that the call is a spam call, terminating the call.