Speech synthesizers are transforming workplace culture. A speech synthesis reads the text. Text-to-speech is when a computer reads a word aloud. It is to have machines talk simply and sound like people of different ages and genders. Text-to-speech engines are becoming more popular as digital services, and voice recognition grow.

What is speech synthesis?

Speech synthesis, also known as text-to-speech (TTS system), is a computer-generated simulation of the human voice. Speech synthesizers convert written words into spoken language.

Throughout a typical day, you are likely to encounter various types of synthetic speech. Speech synthesis technology, aided by apps, smart speakers, and wireless headphones, makes life easier by improving:

What is the history of speech synthesis?

How does Speech Synthesis Work?

Speech synthesis works in three stages: text to words, words to phonemes, and phonemes to sound.

1. Text to words

Speech synthesis begins with pre-processing or normalization, which reduces ambiguity by choosing the best way to read a passage. Pre-processing involves reading and cleaning the text, so the computer reads it more accurately. Numbers, dates, times, abbreviations, acronyms, and special characters need translation. To determine the most likely pronunciation, they use statistical probability or neural networks.

Homographs—words that have similar pronunciations but different meanings require handling by pre-processing. Also, a speech synthesizer cannot understand “I sell the car” because “sell” can be pronounced “cell.” By recognizing the spelling (“I have a cell phone”), one can guess that “I sell the car” is correct. A speech recognition solution to transform human voice into text even with complex vocabulary.

2. Words to phonemes

After determining the words, the speech synthesizer produces sounds containing those words. Every computer requires a sizeable alphabetical list of words and information on how to pronounce each word. They’d need a list of the phonemes that make up each word’s sound. Phonemes are crucial since there are only 26 letters in the English alphabet but over 40 phonemes.

In theory, if a computer has a dictionary of words and phonemes, all it needs to do is read a word, look it up in the dictionary, and then read out the corresponding phonemes. However, in practice, it is much more complex than it appears.

The alternative method involves breaking down written words into graphemes and generating phonemes that correspond to them using simple rules.

3. Phonemes to sound

The computer has now converted the text into a list of phonemes. But how do you find the basic phonemes the computer reads aloud when it converts text to speech in different languages? There are three approaches to this.

Concatenative Synthesis

Speech synthesizers that use recorded human voices must be preloaded with a small amount of human sound that can be manipulated. Also, it is based on human speech that has been recorded.

What is Formant Synthesis?

Formants are the 3-5 key (resonant) frequencies of sound generated and combined by the human vocal cord to produce the sound of speech or singing. Formant speech synthesizers can say anything, including non-existent and foreign words they’ve never heard of. Additive synthesis and physical modeling synthesis are using for generating the synthesized speech output.

What is Articulatory synthesis?

Articulatory synthesis is making computers speak by simulating the intricate human vocal tract and articulating the process that occurs there. Because of its complexity, it is the method that the least researchers have studied the least until now.

In short, voice synthesis software/ text-to-speech synthesis allows users to see written text, hear it, and read it aloud all at the same time. Different software makes use of both computer-generated and human-recorded voices. Speech synthesis is becoming more popular as the demand for customer engagement and organizational process streamlining grows. It facilitates long-term profitability.