About the reference guide

SpeechKit is a multi-platform library for adding speech functionality to your mobile apps with minimal effort.

The ultimate goal of SpeechKit is to provide users with virtually the entire range of speech functionality available to Yandex.

In this release, Yandex SpeechKit offers server-side speech recognition functionality for short voice queries (only Russian and Turkish are supported).

Components

In order to simplify integration while keeping detailed control over the functionality, Yandex.SpeechKit offers two versions of the API. The first is a simplified API (RecognizerActivity) with a default GUI. The second is an advanced API (Recognizer and Initializer) with extended management of the library functionality.

The simplified API consists of just one class:

The advanced API provides the following main classes:

  • Recognizer — An interface for accessing the speech recognition function.

  • Initializer — An interface for controlling the initialization process.

Regardless of which API you choose, SpeechKit must be configured using:

  • SpeechKit — An interface for configuring the library and controlling overall operation.

SpeechKit

The SpeechKit class is a tool for configuring and managing SpeechKit.

Before using any of the speech recognition functionality, you must configure SpeechKit using SpeechKit.configure with your API key. For information about getting an API key, see the API keys section.

RecognizerActivity

This class is an Android Activity that is designed to simplify integration of speech recognition in applications. RecognizerActivity returns the string uttered by the user and resolves any problems that occur along the way. RecognizerActivity manages the entire recognition process, including the user interface for speech recognition, management of the Recognizer and Initializer objects, and so on.

RecognizerActivity starts up using the Android startActivity method that passes the corresponding Intent, and returns recognition results using the resulting Intent.

Recognizer

Recognizer is the central component of speech recognition in SpeechKit. Recognizer is intended for single sessions of speech recognition. It manages the entire recognition process, including recording audio, detecting speech activity, communicating with the server, and so on. Recognizer uses the RecognizerListener interface for notification of important events in the recognition process, returning recognition results, and notification of errors.

The recognition result is represented by the Recognition class, which is the “N-best list” of recognition hypotheses, sorted by confidence in descending order. A recognition hypothesis, in turn, is represented by the RecognitionHypothesis class.

The Error class describes the errors that occurred during the recognition process.

Initializer

Initialization is the internal process that SpeechKit uses for initializing internal mechanisms. Initialization may require executing lengthy read operations from permanent memory or network access, and generally takes a significant amount of time. This is why the Initializer class has been introduced for performing initialization when it is convenient for the user.

In the current implementation, Initializer sends a request to the server (the “startup request”) and gets a response with a set of parameters and configurations (for example, the confidence thresholds), which are then used during speech recognition.

Note. Users do not have to perform initialization explicitly. If it has not yet been done, SpeechKit initializes itself automatically when the first request for speech recognition is received. So Initializer is used mainly in order to speed up the execution of the first request.

Initializer uses the InitializerListener interface to notify you when it starts and finishes (with or without errors).

The Error class describes the errors that occurred during the recognition process.