Speech Android

On-device speech SDK for Android and embedded Linux, powered by ONNX Runtime and speech-core.

Speech recognition (114 languages), text-to-speech, voice activity detection, and noise cancellation — all running locally. No cloud APIs, no data leaves the device.

Models · speech-swift (Apple counterpart) · speech-core (pipeline engine)

Platforms

Platform	API	Acceleration	Directory
Android	Kotlin (SpeechPipeline)	NNAPI (Snapdragon, Exynos, Tensor)	sdk/
Embedded Linux	C (speech.h)	QNN (Hexagon DSP)	linux/

Models

Model	Task	INT8 Size	Languages
Parakeet TDT v3	Speech recognition	891 MB	114
Kokoro 82M	Text-to-speech	330 MB	English
Silero VAD v5	Voice activity detection	2 MB	Any
DeepFilterNet3	Noise cancellation	~8 MB	Any

Models are downloaded automatically on first launch (Android) or placed manually (Linux).

Android

Add dependency

dependencies {
    implementation("audio.soniqo:speech:0.0.1")
}

Usage

val modelDir = ModelManager.ensureModels(context)

val pipeline = SpeechPipeline(
    SpeechConfig(modelDir = modelDir, useNnapi = true)
)

pipeline.events.collect { event ->
    when (event) {
        is SpeechEvent.TranscriptionCompleted -> println(event.text)
        is SpeechEvent.ResponseDone -> pipeline.resumeListening()
        else -> {}
    }
}

pipeline.start()

// Feed 16kHz mono float32 PCM from microphone
pipeline.pushAudio(samples)

Build from source

git clone --recursive https://github.com/soniqo/speech-android.git
cd speech-android
./setup.sh
./gradlew :app:assembleDebug
./gradlew :sdk:connectedDebugAndroidTest   # 18 e2e tests

Embedded Linux

Minimal C API for automotive and embedded platforms. See linux/README.md for full documentation.

Usage

#include <speech.h>

void on_event(const speech_event_t* event, void* ctx) {
    if (event->type == SPEECH_EVENT_TRANSCRIPTION)
        printf("%s\n", event->text);
}

speech_config_t cfg = speech_config_default();
cfg.model_dir = "/opt/speech/models";
cfg.use_qnn = true;  // Hexagon DSP acceleration

speech_pipeline_t p = speech_create(cfg, on_event, NULL);
speech_start(p);
speech_push_audio(p, pcm_samples, 512);

Build

cd linux && ./setup_linux.sh
cmake -B build -DORT_DIR=../ort-linux
cmake --build build
./build/speech_demo --model-dir /path/to/models

Cross-compile for Yocto

source /opt/poky/environment-setup-aarch64-poky-linux
cmake -B build -DCMAKE_TOOLCHAIN_FILE=toolchain-aarch64.cmake -DORT_DIR=...
cmake --build build

Pipeline

Idle → Listening → Transcribing → Speaking → Idle
              ↑                         |
              └─── resumeListening() ───┘

Barge-in supported: speaking during TTS playback interrupts and starts a new transcription.

Architecture

┌──────────────────────────────────────────────┐
│   Android: SpeechPipeline (Kotlin/JNI)       │
│   Linux:   speech.h (C API)                  │
└──────────────────┬───────────────────────────┘
                   │
┌──────────────────┴───────────────────────────┐
│            speech-core (C++ submodule)        │
│   Turn detection · Interruptions · Context   │
└──┬────────┬────────┬────────┬────────────────┘
   │        │        │        │  vtables
┌──┴──┐  ┌──┴──┐  ┌──┴──┐  ┌─┴────────┐
│ VAD │  │ STT │  │ TTS │  │ Enhancer │
│Silero│  │Para-│  │Koko-│  │DeepFilter│
│     │  │keet │  │ro   │  │Net3      │
└──┬──┘  └──┬──┘  └──┬──┘  └─┬────────┘
   └────────┴────────┴────────┘
       ONNX Runtime (CPU / NNAPI / QNN)

Hardware Acceleration

Platform	Chipset	Acceleration
Android	Snapdragon 8 Gen 1+	NNAPI → Hexagon NPU
Android	Samsung Exynos 2200+	NNAPI → Samsung NPU
Android	Google Tensor G2+	NNAPI → Google TPU
Automotive	SA8295P / SA8255P	QNN → Hexagon DSP
Any	CPU fallback	XNNPACK

Related

Repository	Platform
speech-swift	Apple (macOS, iOS) — MLX + CoreML
speech-core	Cross-platform C++ pipeline engine
speech-android	Android + embedded Linux — ONNX Runtime

License

Apache 2.0