Speech is the most important invention in the history of humanity; speech is one of the major characteristics that distinguish humans from other animal species. Speech helps us communicate effectively with each other, and in the recent past we have been able to develop software that allows us to communicate with computers in the same way we communicate with our fellow human beings. Speech recognition is a rapidly developing technology used everywhere. Speech recognition speech recognition is the process by which the words spoken by the speaker are translated into text format by computer software. Speech recognition systems can be broadly classified into two types, one being speaker independent systems where the system can recognize the speech of any speaker and translate it into text format, and these systems can be used to generic purposes where multiple users attempt to communicate with the voice recognition system. The second is a speaker-dependent system and, as the name suggests, it is a system specific to a single or limited set of users. The system is trained to recognize a single or specific set of users by asking them to speak words specified to the system, which stores the words and analyzes the speaker's voice and adjusts it to recognize the speaker's voice in a future instance . Speech recognition has a wide range of uses and areas of focus, some of the major areas where speech recognition is widely used are security, navigation, etc. Speech recognition is like any other software and requires an algorithm as a basis to build into a useful application. Most of the new age speech recognition applications are based on Hidden Markov Models. Algorithms As stated earlier...... middle of article...... effectiveness of the training process. Many armies such as USAF, US Navy, US Army, Royal Australian Air Force, etc. use voice recognition technology to train their traffic controllers, which are provided by various vendors. People with Disabilities Speech recognition is a boon for many people who have a hearing problem, speech recognition applications can help present conversations in a meeting room, classroom or services in a quick and accurate format for users with hearing difficulties. The use of keyboards for documenting can also be reduced to a large extent through the use of voice recognition. The days are not far away when you can command your microwave to turn off, your air conditioning to change the temperature, or ask your washing machine to wash your clothes. . Speech recognition will play an important and active role in our lives in the future.