Principle:Elevenlabs Elevenlabs python Audio Interface
| Knowledge Sources | |
|---|---|
| Domains | Audio_Processing, Conversational_AI, Hardware_Abstraction |
| Last Updated | 2026-02-15 00:00 GMT |
Overview
An abstraction layer that provides bidirectional audio I/O (microphone input and speaker output) for real-time conversational AI sessions, with support for buffered output and interruption handling.
Description
Audio Interface is the hardware abstraction layer for conversational AI. It manages two audio streams simultaneously:
- Input stream: Captures microphone audio as 16-bit PCM mono at 16kHz and delivers it to the conversation handler via callbacks
- Output stream: Receives synthesized agent audio and plays it through speakers with buffering and interruption support
The interface follows the Abstract Base Class pattern, defining four methods that any audio implementation must provide: start, stop, output, and interrupt. This decouples the conversation logic from the specific audio hardware or library used, allowing custom implementations for different platforms (e.g., browser WebRTC, mobile audio APIs, virtual audio devices).
The default implementation uses PyAudio for cross-platform microphone and speaker access, with a dedicated output thread for non-blocking playback and a queue-based buffer for interruption support.
Usage
Use this principle when building a real-time voice conversation with an ElevenLabs agent. The audio interface must be provided to the Conversation constructor and handles all audio I/O for the session. Use the default implementation for standard microphone/speaker setups, or implement the ABC for custom audio sources and sinks.
Theoretical Basis
The Audio Interface follows the Strategy pattern with an ABC defining the contract:
# Abstract interface contract
class AudioInterface(ABC):
def start(input_callback): # Begin capture, call input_callback(audio_bytes)
def stop(): # Clean up resources
def output(audio_bytes): # Play agent audio (non-blocking)
def interrupt(): # Stop current playback immediately
Key design considerations:
- Non-blocking output: output() must return quickly; actual playback happens in a separate thread
- Interruption support: When the user speaks over the agent, all buffered audio must be discarded immediately
- PCM format: 16-bit signed integer, mono channel, 16kHz sample rate is the fixed audio format