Non-looping sleep sound app with on-device audio generation for improved sleep quality
Industry
Services
Duration
Team size
About the client
Adaptive Sound Technologies, Inc. (ASTI) is a Silicon Valley-based company and the world's leading supplier of advanced sound machines and adaptive audio products.
Founded in 2008, ASTI developed the Sound+Sleep and LectroFan product lines, sleep devices trusted by customers worldwide for delivering consistent, high-quality audio environments.
The company holds multiple patents covering advances in ambient noise analysis and dynamic adaptive audio technology, the result of years of hardware engineering work on its product lines.
Business challenge
ASTI's audio engine generates sound in real time with no loops or repetition, but it lived only inside hardware. The goal was to bring it to mobile as a standalone sleep-sound app.
ASTI's business model centers on manufacturing and distributing physical sound machines, which carries the cost and complexity of production, logistics, and shipping to every market. A mobile app changes the economics: software distributes instantly through the App Store and Google Play, letting ASTI reach new markets and customer segments without moving physical products.
The hard part was not building the app itself. It was bringing a patent-protected, C-based audio engine, designed to run on dedicated hardware, into a modern mobile framework while preserving that behavior and keeping it simple enough to use at bedtime. ASTI needed a development partner with the technical depth to own the integration, build the app architecture, and support ongoing OS compatibility as the platform grows.
Delivered solution
Orangesoft built Sleep Only, an iOS and Android sleep-sound application that brings ASTI's proprietary non-looping audio technology to mobile devices for the first time.
Built in Flutter for a single cross-platform codebase, the app delivers the full user experience: onboarding, sound browsing, favorites, settings, subscriptions, and library download management. The sound itself is generated on-device by ASTI's patent-protected audio engine, with no pre-recorded files.
The result is a sleep app that needs no streaming, no loops, and no internet connection for playback. By keeping audio generation local, the app eliminates the loop-transition artifact entirely, addressing a core limitation that other sleep apps cannot solve in software.
Technical challenge
The primary engineering challenge was integrating ASTI's proprietary C audio library into a Flutter application without compromising real-time performance.
Flutter is ideal for the app layer, but real-time audio from a C engine needs native-level timing, plus microphone capture, audio session handling, and locked-screen background playback that Flutter's bridge cannot deliver without latency. Orangesoft used a hybrid architecture: Flutter handles the app layer, while native Kotlin and Swift components own the audio path, integrated directly with the libasti engine and connected via MethodChannel.
Adaptive Sound builds on this, processing live microphone input through ASTI's algorithm and applying seamless volume adjustments in the native pipeline. To keep it reliable across a fragmented device landscape, the team built in per-device calibration, QA diagnostic tooling, and coverage of real-world interruptions such as calls, alarms, and Bluetooth. This integration work drove the bulk of the project timeline.
Core features
Designed for simplicity at bedtime, the app is built around a few features that work together to support better sleep.
Simple, sleep-friendly interface
Sound profiles are organized into groups with favorites for quick access and a 30-second preview before committing to a sound. The UI is dark-mode-first, designed for use in the dark without disruptive transitions.
Adaptive sound mode
The app’s microphone analyzes ambient noise in real time and automatically adjusts playback volume to compensate for sudden disruptions, without any user input. Volume transitions are gradual, and sensitivity thresholds are adjustable.
Shut-off timer and background audio
A configurable shut-off timer stops playback automatically after a set duration, so audio doesn’t run all night. Sound generation continues in the background while the phone is locked, with no screen activity required.
Technology stack
Mobile
Flutter
Dart
Riverpod
Kotlin
Swift
C (libasti)
Backend
Firebase Auth
Cloud Firestore
Firebase Storage
Firebase Crashlytics
RevenueCat
Project results
Orangesoft delivered a production-ready iOS and Android application that, for the first time, brings ASTI's core hardware differentiator to a cross-platform mobile product.
Sleep Only gives the company a direct-to-consumer software channel, extending the reach of its patented audio technology beyond standalone devices and positioning ASTI to compete in the rapidly growing mobile sleep market.
Sleep Only is now live on the App Store and Google Play. Orangesoft has been gathering early feedback and shipping improvements since launch and remains engaged as the long-term development partner, supporting post-launch maintenance, OS compatibility updates, and ongoing feature development.
Kickstart your digital journey today!
Add your brand's success story to our global list of disruptive brands.
Join the clubWe're trusted by: