Leopard Speech-to-Text
Node.js Quick Start

Platforms

• Linux (x86_64)
• macOS (x86_64, arm64)
• Windows (x86_64, arm64)
• Raspberry Pi (3, 4, 5)

Requirements

• Picovoice Account & AccessKey
• Node.js 18+
• npm

Picovoice Account & AccessKey

Signup or Login to Picovoice Console to get your AccessKey. Make sure to keep your AccessKey secret.

Quick Start

Setup

1. Install Node.js.

2. Install the leopard-node npm package:

npm install @picovoice/leopard-node

Usage

Create an instance of the engine:

const Leopard = require("@picovoice/leopard-node");

const accessKey = "${ACCESS_KEY}";
const leopard = new Leopard(accessKey);

Transcribe an audio file by providing an absolute path to the file:

const { transcript, words } = leopard.processFile("${AUDIO_FILE_PATH}");

Transcribe raw audio data (sample rate of 16 kHz, 16-bit linearly encoded and 1 channel):

const getAudioData = () => {
  // ...
}

const { transcript, words } = leopard.process(getAudioData());

Free resources used by Leopard Speech-to-Text:

leopard.delete()

Model File

The Leopard Speech-to-Text Node.js SDK comes preloaded with a default English language model (.pv file). Default models for other supported languages can be found in the Leopard Speech-to-Text GitHub repository.

Create custom language models using the Picovoice Console. Here you can train language models with custom vocabulary and boost words in the existing vocabulary.

Pass in the .pv file via the modelPath parameter in the options argument of the Leopard Speech-to-Text constructor:

const handle = new Leopard(accessKey, { modelPath: "${MODEL_PATH}"});

Word Metadata

Along with the transcript, Leopard Speech-to-Text returns metadata for each transcribed word. Available metadata items are:

• Start Time: Indicates when the word started in the transcribed audio. Value is in seconds.
• End Time: Indicates when the word ended in the transcribed audio. Value is in seconds.
• Confidence: Leopard Speech-to-Text's confidence that the transcribed word is accurate. It is a number within [0, 1].
• Speaker Tag: If speaker diarization is enabled on initialization, the speaker tag is a non-negative integer identifying unique speakers, with 0 reserved for unknown speakers. If speaker diarization is not enabled, the value will always be -1.

Demo

For the Leopard Speech-to-Text Node.js SDK, we offer demo applications that demonstrate how to use the Speech-to-Text engine on audio files.

Setup

Install the Leopard Speech-to-Text demo package:

npm install -g @picovoice/leopard-node-demo

This package installs command-line utilities for the Leopard Speech-to-Text Node.js demos.

Usage

Use the --help flag to see the usage options for the demo:

leopard-file-demo --help

Run the following command to transcribe an audio file:

leopard-file-demo --access_key ${ACCESS_KEY}
                  --input_audio_file_path ${AUDIO_PATH}

For more information on our Leopard Speech-to-Text demos for Node.js, head over to our GitHub repository.

Resources