A couple of years ago, I bought myself a really cool gadget. This gadget would change my life – how I connected with people, how I worked, and what I did for fun. Curious? I bet you have it too. It’s a smartphone. I bring this up because I became aware of text-to-speech (TTS) for the first time thanks to my smartphone.
Once I tried TTS, I saw a whole world of possibilities that could change the way we handled everyday tasks. How do you ask? Let’s find out.
The Concept of Text-To-Speech (TTS)
As the word implies, text-to-speech systems simply convert text into speech. When you type a word into such a program, it converts that text into the audible forms, like your own personal book reader. It is also known as speech synthesis. Speech synthesis involves 3 processes:
#1 Text to words: Reading might sound easy, but in fact, it is a very complex process. Humans have a general idea of how words might sound, but computers have to work this out mathematically. The first step here is to convert the input text into words. When you type something in the TTS system, it has to put the text together, reading all the spaces and punctuation in between, and comprehend the words and sentences they spell.
#2 Words to phonemes: The word phoneme sounds complex but it’s easy to understand. Just as letters of the alphabet make up words in written language, phonemes make up the words in spoken language. They are the sounds in words. For example, the sounds “/lʌ” and “ʌk/” make up the word “luck”. The computer takes the words that it recognizes and turns it into these phonemes.
#3 Phonemes to sound: Now that the computer has understood what phonemes go to what word, it can now convert them into sound by synthesizing the phonemes and putting them together. It does this in 3 ways:
- Concatenative: The computer can use pre-recorded human voice samples.
- Formant: The sounds can be digitally synthesized, much like a music synthesizer.
- Articulatory: This is a much more complex and less used method where the computer generates speech by mimicking a human voice by using a device that has moving or vibrating parts such as a vocal cord. A robotic talking head is an ideal example.
Applications of Text-to-Speech
TTS has a whole world of amazing possibilities, especially since it’s very easy to access, by using computer software, smartphone apps, and even free online text to speech tools.
- Helping people with hearing and speech disabilities communicate with others
- GPS navigation systems are used practically every day while people commute
- Helping children with Dyslexia who find reading and writing difficult,
- Helping people with vision impairments read written text. It helps them type by using software that speaks out words as they are press keys on the keyboard. Such systems find their use in schools for the blind.
With further research into TTS being undertaken by tech companies, the range of its applications will only widen in the future. The possibilities are endless.