## General Information about Sphinx-4

- Introduction

  Sphinx-4 is a state-of-the-art speech recognition system written entirely in the JavaTM programming language. It was created via a joint collaboration between the Sphinx group at Carnegie Mellon University, Sun Microsystems Laboratories, Mitsubishi Electric Research Labs (MERL), and Hewlett Packard (HP), with contributions from the University of California at Santa Cruz (UCSC) and the Massachusetts Institute of Technology (MIT).

  Sphinx-4 started out as a port of Sphinx-3 to the Java programming language, but evolved into a recognizer designed to be much more flexible than Sphinx-3, thus becoming an excellent platform for speech research.

- Capabilities

  Live mode and batch mode speech recognizers, capable of recognizing discrete and continuous speech.

  Speech aligner for aligning speech to text.

  Various tools to work with the speech including the tools to display spectograms, detect silence and extract features

- Performance

  Sphinx-4 is a very flexible system capable of performing many different types of recognition tasks. As such, it is difficult to characterize the performance and accuracy of Sphinx-4 with just a few simple numbers such as speed and accuracy. Instead, we regularly run regression tests on Sphinx-4 to determine how it performs under a variety of tasks fro simple grammar recognition to large vocabulary speech recognition

## Installation

Required Software

Sphinx-4 has been built and tested on the Solaris TM Operating Environment, Mac OS X, Linux and Win32 operating systems. Running, building, and testing Sphinx-4 requires additional software. Before you start, you will need the following software available on your machine.

- Java SE 6 Development Kit or better. Go to java.sun.com, and select "J2SE" from popular downloads. At the time of writing, the latest release version is JDK 6 Update 14, which is the one we recommend.

- Apache maven or better, available at maven.apache.org. The site has a manual with instructions on how to download, install, and use ant. You will only need ant if you wish to build Sphinx-4 from the source distribution.
- Subversion (svn), but only if you want to interact directly with the svn tree (which we recommend). The canonical places to get it is subversion.tigris.org. If you are using Windows, your best choice is to install cygwin, which will give you a linux-like environment in a command prompt window. Make sure to choose "svn" when you install cygwin.

## Demos

Sphinx-4 contains a number of demo programs. You can find them in sphinx4-samples package.

- Transcriber - transcribe speech file
- Dialog - interact with the user commands
- Aligner - align speech to text

## Sphinx-4 in Detail

Sphinx-4 Whitepaper Sphinx-4: A Flexible Open Source Framework for Speech Recognition describes the framework and implementation of Sphinx-4 from a speech-technologist's perspective. Please read this if you'd like to extend Sphinx-4.