Steerable Surveillance Audio Playback Using Microphone Arrays

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Solution Overview

Problem

Surveillance systems face challenges in synchronizing audio capture with video capture and steering audio playback, as conventional CCTV systems typically have a single microphone per camera, limiting the ability to adjust audio capture and playback directions independently of video adjustments.

Innovation Solution

Implementing a microphone array with multiple audio capture devices coupled to a video capture device, utilizing digital signal processing (DSP) to determine and apply directional instructions for both capture and playback, allowing for virtual capture and playback directions to be steered as needed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single microphone is attached to each camera in a CCTV system, then the system structure is simple, but the operator cannot synchronize audio capture with video capture or steer audio playback independently

Engineering Contradiction:

Improveaudio capture direction controlVSAvoidmicrophone array structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The audio capture function is segmented into multiple independent microphones arranged in an array, allowing each microphone to capture audio from different spatial positions. This segmentation enables the system to synthesize directional audio capture by selectively combining signals from individual microphones, thereby achieving steerable audio capture without requiring a single complex directional microphone for each camera.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A processing device acts as an intermediary between the microphone array and the output audio stream. This processing device receives audio signals from multiple microphones, applies digital signal processing to synthesize directional audio capture, and generates the final audio output. The intermediary processing device enables flexible audio direction control while keeping the physical microphone array structure relatively simple.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If conventional CCTV systems use a single microphone per camera, then the device complexity is low, but audio-video synchronization and steerable audio playback are not achievable

Engineering Contradiction:

Improveaudio direction adjustmentVSAvoidaudio capture system

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces mechanical directional control (physically moving or rotating a single microphone) with digital signal processing. Instead of mechanically adjusting microphone orientation, the system uses software-based beamforming and signal synthesis to achieve directional audio capture and steerable audio playback, significantly improving ease of operation while reducing mechanical complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The audio capture direction is made dynamic and adjustable in real-time through digital signal processing. The processing device can change the synthesized direction of audio capture on-demand based on operator input or video frame analysis, allowing the audio direction to adapt dynamically without physical movement of hardware components.

Inventive Principle:

Principle #15Dynamics

3Reliability

If a microphone array with multiple audio capture devices is implemented, then audio-video synchronization and steerable audio are achieved, but the device complexity increases

Engineering Contradiction:

Improveaudio-video synchronizationVSAvoidmicrophone array and processing system

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the audio capture functionality across multiple microphones into a unified directional audio stream through digital signal processing. By combining signals from multiple microphones with synchronized timing, the system achieves reliable audio-video synchronization and produces a single coherent audio output that can be steered independently of video adjustments.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS12498898B2Steering audio recordings in a surveillance system

Publication Date: 2025.12.16 TYCO FIRE & SECURITY GMBH

AI summary

A system may be configured to implement directional audio playback via digital signal processing on recorded audio. In some aspects, the system may include a processing device. Further, the processing device may be configured to select audio information for audio playback, the audio information including a plurality of audio captures of a microphone array, and determine directional instruction information for the audio playback, the directional instruction information identifying a virtual playback direction. In addition, the processing device may be further configured to generate a digital signal processing (DSP) plan based on the virtual playback direction, and apply the processing plan to the plurality of audio captures to produce the audio playback corresponding to the virtual playback direction.