SyncRecord1.1.0

Turn multiple smartphones into a synchronized, ad-hoc microphone array for capturing sound from separate locations. A session starts on one master device, while other phones join with a unique alphanumeric session ID. The devices play audible pseudo-random binary sequence signals, then use cross-correlation of the recordings to calculate propagation delays, align capture times, and estimate distances between devices.

Its synchronized recording mode localizes the phones while capturing simultaneous raw, unprocessed audio, producing time-aligned, multi-channel archives for later analysis. The separate localise-array-devices mode maps the devices’ geometric arrangement without retaining continuous audio streams. Server-side signal processing handles calibration, automatically estimating inter-device distances and correcting timing offsets; under the stated test conditions, alignment reached within 52 samples at 48 kHz and distance estimates were within 14 millimetres.

SyncRecord suits acoustic researchers, sound-source localization work, and other projects that need recordings from several positions without a traditional hardware microphone array. It supports either a cloud-based demonstration server or a locally hosted server, with local deployment providing greater control over data handling and lower latency; cloud-session audio is deleted immediately after the session ends, and cloud use requires no user login.

The current 1.1.0 release is SyncRecord’s initial release, introducing synchronized multi-device recording, automatic calibration, and inter-device distance estimation. It runs on Android 10 or later with Universal architecture and is open-source under the MIT License.