Decibri

Cross-platform audio capture, playback, and processing for Python.

Decibri is a native Python package that delivers microphone capture, speaker output, local voice activity detection, device enumeration, and sample format conversion. It is written in Rust (via PyO3 / abi3) and ships pre-built wheels for Linux, macOS Apple Silicon, and Windows.

Install

Recommended with uv:

uv pip install decibri

Or with pip:

pip install decibri

Quickstart

Capture audio

import decibri

with decibri.Microphone(sample_rate=16000, channels=1) as mic:
    for chunk in mic:
        print(f"Got {len(chunk)} bytes")
        break  # exit after first chunk for demo

Record one second to a WAV file

import decibri

decibri.record_to_file("output.wav", duration_seconds=1.0, sample_rate=16000)

Condition and analyze a recording

import decibri

# The same conditioning chain as the live microphone, over a WAV file.
with decibri.File("clip.wav", denoise="fastenhancer-t", highpass=80) as file:
    for chunk in file:
        handle(chunk)          # conditioned int16 PCM bytes

# Whole-file speech analysis (a live stream cannot do this).
report = decibri.File("clip.wav", vad="silero").analyze()
for segment in report.segments:
    print(segment.start, segment.end)   # seconds of file time

Capture with Silero VAD

import decibri

with decibri.Microphone(sample_rate=16000, vad="silero") as mic:
    for chunk in mic:
        print(f"Got {len(chunk)} bytes; VAD score {mic.vad_score}; speaking={mic.is_speaking}")
        break  # exit after first chunk for demo

Async capture

import asyncio
import decibri

async def main():
    async with await decibri.AsyncMicrophone.open(sample_rate=16000, vad="silero") as mic:
        async for chunk in mic:
            print(f"Got {len(chunk)} bytes; VAD score {mic.vad_score}")
            break  # exit after first chunk for demo

asyncio.run(main())

Speaker output

import decibri

with decibri.Speaker(sample_rate=24000, channels=1) as spk:
    audio_bytes = b"\x00\x00" * 24000  # 1 second of silence at 24kHz int16
    spk.write(audio_bytes)  # int16 PCM
    spk.drain()

Public API

Core classes

• Microphone: synchronous audio capture
• Speaker: synchronous audio output
• File: offline source; conditions a recording or in-memory samples and analyzes it for speech
• AsyncMicrophone: async-await audio capture
• AsyncSpeaker: async-await audio output
• AsyncFile: async-await offline source

Module-level functions

• decibri.input_devices(): enumerate available input devices
• decibri.output_devices(): enumerate available output devices
• decibri.version(): version + audio backend info
• decibri.record_to_file(path, duration_seconds, ...): record N seconds to a WAV file
• decibri.async_record_to_file(path, duration_seconds, ...): async equivalent

Value types

MicrophoneInfo, SpeakerInfo, VersionInfo, Chunk, VadReport, VadWindow, Segment.

Exceptions

The full hierarchy lives at decibri.exceptions. Top-level catch-targets surfaced at the package root:

• DecibriError: base of the hierarchy
• DeviceError: input / output device problems
• OrtError: ONNX Runtime issues
• OrtPathError: ORT dylib path resolution issues
• ForkAfterOrtInit: Linux fork-after-ORT-init detection

Voice Activity Detection

Decibri ships with two VAD modes: a lightweight RMS energy threshold (opt-in via vad="energy") and a Silero ONNX model (~2.3 MB, bundled in the wheel; no API keys required). Pass the mode as the vad="silero" / vad="energy" shorthand (which uses the default threshold and a 300 ms holdoff) or as a decibri.Vad(model=, threshold=, holdoff_ms=) config object to tune them.

# Energy mode (lightweight, no model)
mic = decibri.Microphone(vad=decibri.Vad(model="energy", threshold=0.01))

# Silero mode (ML-based, more accurate in noisy environments)
mic = decibri.Microphone(vad=decibri.Vad(model="silero", threshold=0.5))

Use mic.vad_score (a value in [0, 1]) to gate downstream processing. mic.is_speaking returns the boolean above-threshold view.

decibri ACE (audio conditioning)

decibri ACE (Audio Capture Engine) is decibri's opt-in audio front-end for speech: a conditioning chain applied to the captured audio before it is delivered. Every stage is off by default, runs on-device, and needs no API key. Leave the options unset and the capture path is unchanged.

The stages run in this order. Pass any subset on the Microphone constructor:

import decibri

with decibri.Microphone(
    sample_rate=16000,
    denoise="fastenhancer-t",  # bundled speech-enhancement model
    highpass=80,               # remove low-frequency rumble
    agc=-18,                   # target level in dBFS
    limiter=-1.0,              # peak ceiling in dBFS
    vad=decibri.Vad(model="silero", threshold=0.5),
) as mic:
    for chunk in mic:
        if mic.is_speaking:
            handle(chunk)      # conditioned int16 PCM bytes

The denoise model is bundled in the wheel (the same way the Silero VAD model is), so denoise="fastenhancer-t" needs no download. VAD reads the signal before the chain, so mic.vad_score and mic.is_speaking are unaffected by which conditioning stages you enable. The same options are available on AsyncMicrophone.

Files

Everything a Microphone does to live audio, File does to audio you already have: the same conditioning options (dc_removal, denoise, highpass, agc, limiter), the same iteration, the same conditioned chunks out, and the same opt-in vad=. A File reads WAV, AIFF, AIFF-C and FLAC (File("clip.wav"), or the identical File.open("clip.wav"); the container is identified from the file's own bytes rather than its extension) or wraps in-memory samples (File.buffer(samples, input_rate=48000); raw samples carry no header, so their native rate is explicit). sample_rate stays the target output rate, the same meaning it has on Microphone, so a 44.1 kHz recording comes out at 16 kHz unless you set it.

Because a File is a complete recording, it can analyze the whole recording for speech:

report = decibri.File("clip.wav", vad="silero").analyze()   # or .analyse()
for w in report.scores:
    print(w.start, w.end, w.vad_score, w.is_speech)   # per 32 ms window
for segment in report.segments:
    print(segment.start, segment.end)                 # merged speech regions

analyze() requires VAD: a File built without vad= raises VadNotConfigured rather than constructing a detector silently. With vad= set, metadata iteration (iter_with_metadata()) carries per-chunk vad_score and is_speaking exactly as the microphone does, with one deliberate difference: on a File, the speaking holdoff and the Chunk.timestamp are measured in FILE time (sample positions in seconds), never wall-clock time, so a file processed faster than real time still reports correct speech timing. Iteration and analysis are separate single passes; construct one File per operation. AsyncFile mirrors the whole surface with async semantics.

Compatibility

Bundled assets

The wheel includes:

• Silero VAD ONNX model (~2.3 MB): no downloads or API keys required for vad="silero".
• ONNX Runtime dylib (~15-20 MB platform-specific): no system dependency on pip install onnxruntime.

First ORT load on vad="silero" initialization is ~100 to 500 ms (amortized across subsequent calls).

ONNX Runtime telemetry

vad="silero" and the ACE denoise stage run on ONNX Runtime, which carries its own telemetry, separate from anything decibri does. Decibri disables it on the environment it commits when it initializes the runtime. Set DECIBRI_ORT_TELEMETRY=1 in the environment before first use to leave it enabled; every other value, an empty value, and an absent variable leave it disabled.

Two limits apply on Windows and decibri can close neither, so decibri does not claim that no telemetry is emitted. ONNX Runtime logs one process-information event while the environment is being created, before the setting is applied, and logs it once per process, so that event is emitted whichever way the setting is left. The runtime also assigns its telemetry state from the Windows tracing session through an ETW callback, so the platform can re-enable telemetry after decibri has disabled it. On other platforms ONNX Runtime's telemetry provider does nothing.

Async usage

For Silero VAD in async code, use the open() factory to dispatch the synchronous ORT init off the event loop:

async with await decibri.AsyncMicrophone.open(vad="silero") as mic:
    async for chunk in mic:
        ...

Synchronous constructors (AsyncMicrophone(...)) remain supported and unchanged; open() is the recommended pattern when ORT load cost matters.

Multiprocessing

Linux multiprocessing with Silero VAD requires set_start_method('spawn'). Calling fork() after ORT initialization raises ForkAfterOrtInit:

import multiprocessing as mp

mp.set_start_method('spawn')  # required on Linux for Silero

See the ecosystem guides under bindings/python/docs/ecosystem/ (jupyter, docker, multiprocessing) for environment-specific details.

Documentation

• Source code & issues: github.com/decibri/decibri
• CHANGELOG: CHANGELOG.md
• Ecosystem guides (Jupyter, Docker, multiprocessing): under bindings/python/docs/ecosystem/ in the repo

License

Apache-2.0. See LICENSE for details.

Copyright (c) 2026 Decibri.