What is Speech Recognition?
Speech recognition, also known as “speech-to-text”, occurs when a machine or computer program identifies and processes a person’s spoken words and converts them into text displayed on a screen or monitor. The early stages of this technology utilized a limited vocabulary set that included common phrases and words.
As the software and technology around speech recognition has evolved, it is now able to more accurately interpret natural speech as well as identify differences between accents and different languages. While speech recognition has come a long way, there is still much room for improvement.
The terms speech recognition and voice recognition are often used to refer to the same thing. However, the two are different. Speech recognition is used to identify the words someone has spoken. Voice recognition is a biometric technology used to identify a specific person’s voice.
Speech recognition can be used to perform a voice search whereas voice recognition can be used by a doctor to dictate medical transcription reports. If you have ever had to call your internet service provider for assistance, you may recall having to go through a series of voice-activated prompts. The call center uses speech recognition technology to route you to the right department.
Why use speech recognition?
So why would someone need speech recognition? Today, practically everyone owns and operates smart devices, such as cell phones and digital tablets. Speech recognition technology has become one of many features hard-coded into the software of these smart devices, allowing them to comprehend continuous speech and translate it into different actions.
For example, a user can verbally tell their mobile device to “call Mom”, and the device acknowledges the command and performs the desired action in real-time. Another use case is using a digital assistant like Google or Siri to initiate a voice search.
Some other ways people use speech recognition is to play their music hands-free, print documents, record audio, get updates on weather conditions, make travel arrangements, find cooking recipes, and much more.
How does it work?
At this point, you may be thinking that speech recognition is pretty great but how does it actually work? Computers and other devices are equipped with built-in external microphones and other sensors that pick up the words a person may speak, and these components translate the sound waves of a voice into digital information the device can use. Many different computer programs are used to interpret speech.
Speech recognition software interprets the sound spoken by a person, which is then analyzed and sampled to remove any background noise. It then separates the digital information into separate frequencies. The speech recognition software takes this information and attempts to examine and compare the fundamentals with other fundamentals to an extensive library of words, expressions, and sentences. The software then determines what the person said and provides the text output or performs the command.
It is also worth understanding the word error rate or (WER). Word error rate is calculated by the number of errors divided by the number of total words processed. More specifically, a simple formula used to calculate this rate is as follows: Substitutions + Insertions + Deletions divided by the Total Number of words spoken. This calculation was derived from something called the “Levenshtein distance” which involves measuring the distance between two strings. In this scenario, a string can be considered a sequence of letters that form the words within a transcription.
When choosing a speech recognition software, look for low WER scores. The lower the WER score, the more closely it is that the transcript matches the audio. For example, Rev’s speech recognition product has a 14% WER, or an 86% accuracy rate, which beats Google, Amazon, Microsoft, and other major speech-to-text options.
As speech recognition plays an increasingly greater role in our lives, it’s important to understand how it works. If you are looking for your own speech-to-text services, consider the quality of the service you choose. Rev’s leading speech-to-text A.I. and its community of freelance professionals offer quick and affordable speech-to-text services with 99 percent accuracy.