It may surprise some people but speech recognition has been in development since the early 1950s. Of course at that time the ability of the device to recognise speech was very limited and in fact it could only recognise spoken digits. So, with over 50 years of development behind it how far is this technology progressed?

The ability of a computer to recognise the human voice has always been dictated primarily by the software used to interpret the sound waves recorded by the hardware to which the computer is connected. In this regard little has changed. Microphone and sound recording technology is sufficiently advanced that the accuracy of the recording is not in question. What does cause problems is the process of interpretation of the sound waves recorded and the formation of information from the data stored.

Human language is highly interpretive. That is to say the same sounds may have different meanings and it is up to the listener to assign meaning to them. The process of assigning meaning is known as interpretation and is highly complex. Computer software programmers have battled with this problem for decades and it is only in recent times that significant steps have been taken towards solving the problems presented.

Modern voice recognition software is used in a variety of areas. Most notable among these are:

• Telephony
• Military Applications
• Intelligence Gathering
• Health Care
• Supporting Those with Disabilities
• Air Traffic Control

In telephony voice recognition has been successfully employed in mobile phones to dial a number, in automated switchboards to enable users to select a particular connection and also to improve customer service by allowing auto transcription of recorded customer calls. It is this last area that overlaps with intelligence gathering activities and allows a signals monitoring station to maintain effective surveillance over a large number of calls with minimal human intervention. The idea here is that certain keywords will flag a recorded conversation for further investigation by a human operator.

Speech recognition technology has also been successfully employed in a number of high-tech fighter aircraft. Problems with accuracy of interpretation, especially at high G loads, have caused some programs to be withdrawn, however, the technology is still in development. The most notable current implementation of this technology is in the Eurofighter Typhoon. The limitations of speech recognition technology still mean that individual pilot profiles must be created to match the individual voice but nevertheless the program is viewed as being successful as it enables a reduction in the overall pilot workload. Pilots can assign targets and pass this information on to wingmen all in a manner automated by speech recognition technology.

Thankfully voice recognition has not just been employed for military and destructive purposes. It has also been used successfully to assist the medical profession when recording and transcribing case notes or other medical information. Due to the highly specialised nature of the vocabulary used by the medical profession this software is complicated to produce and expensive to purchase.

The programs used to support those with disabilities are generally cheaper and slightly more limited in scope. The costs here are mostly generated by the human-machine interface that is necessary to act upon the interpreted words and instructions. One application to which voice recognition technology has been successfully employed is that of supporting quadriplegics in motorised wheelchairs. The interpretation of verbal commands here enabling the user to guide and direct the wheelchair in the direction required.

Although speech recognition technology has come on in leaps and bounds over recent years it is still far from perfect. The day is definitely coming though when we will have the ability to command the technology we use in our daily life by voice alone.

Dave Felton writes extensively on a number of websites but has only recently discovered the benefits that speech recognition software can bring to his writing life. Read more of his articles at http://hubpages.com/profile/Conflagrant