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Overview

Neuphonic provides high-quality text-to-speech synthesis through two service implementations:

• NeuphonicTTSService: WebSocket-based implementation with interruption support
• NeuphonicHttpTTSService: HTTP-based implementation for simpler use cases

Both services support various voices, languages, and customization options.

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Installation

To use Neuphonic TTS services, install the required dependencies:

pip install "pipecat-ai[neuphonic]"

You’ll also need to set up your Neuphonic API key as an environment variable: NEUPHONIC_API_KEY

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NeuphonicTTSService (WebSocket)

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Configuration

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InputParams

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NeuphonicHttpTTSService (HTTP)

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Configuration

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Input

Both services accept text input through their TTS pipeline.

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Output Frames

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TTSStartedFrame

Signals the start of audio generation.

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TTSAudioRawFrame

Contains generated audio data:

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TTSStoppedFrame

Signals the completion of audio generation.

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ErrorFrame

Sent when an error occurs during TTS generation:

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Methods

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WebSocket Implementation

The WebSocket implementation (NeuphonicTTSService) inherits from InterruptibleTTSService and provides:

• Support for interrupting ongoing TTS generation
• Automatic websocket connection management
• Keep-alive mechanism for persistent connections
• Special handling for conversation flows

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HTTP Implementation

The HTTP implementation (NeuphonicHttpTTSService) inherits from TTSService and provides:

• Simpler API integration using HTTP streaming
• Less overhead for single TTS requests
• Simplified error handling

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Language Support

Neuphonic TTS supports the following languages:

Regional variants (e.g., EN_US, ES_ES) are automatically mapped to their base language.

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Usage Example

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WebSocket Implementation

from pipecat.services.neuphonic.tts import NeuphonicTTSService
from pipecat.transcriptions.language import Language

# Configure service
tts = NeuphonicTTSService(
    api_key="your-neuphonic-api-key",
    voice_id="preferred-voice-id",
    params=NeuphonicTTSService.InputParams(
        language=Language.EN,
        speed=1.2
    )
)

# Use in pipeline
pipeline = Pipeline([
    ...,
    llm,
    tts,
    transport.output(),
])

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HTTP Implementation

from pipecat.services.neuphonic.tts import NeuphonicHttpTTSService
from pipecat.transcriptions.language import Language

# Configure service
tts = NeuphonicHttpTTSService(
    api_key="your-neuphonic-api-key",
    voice_id="preferred-voice-id",
    params=NeuphonicHttpTTSService.InputParams(
        language=Language.ES,
        speed=1.0
    )
)

# Use in pipeline
pipeline = Pipeline([
    ...,
    llm,
    tts,
    transport.output(),
])

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Metrics Support

Both services support metrics collection:

• Time to First Byte (TTFB)
• TTS usage metrics
• Processing duration

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Audio Processing

• Configurable sample rate (defaults to 22050Hz)
• PCM linear encoding
• Single channel (mono) output
• Base64 decoding for audio data

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Notes

• WebSocket implementation includes a keep-alive mechanism (10-second interval)
• WebSocket service maintains a persistent connection for faster responses
• Both services automatically select appropriate language codes
• The WebSocket implementation pauses frame processing during speech generation to prevent overlapping responses