Text to Speech (TTS) Conversion: Advantages and Disadvantages

This page explores the advantages and disadvantages of Text to Speech (TTS) conversion. It details the benefits and drawbacks associated with this technology.

What is Text to Speech Conversion?

Introduction: Text-to-speech synthesis converts arbitrary input text into intelligible and natural-sounding speech.

Text-to-speech conversion is a valuable hardware and software tool used in various applications, including:

• Vocal monitoring systems for the visually impaired
• Web browsers
• Mobile phones
• PCs
• Laptops

Image alt: Text to Speech Conversion Block Diagram

The figure above illustrates a block diagram comprised of two key parts: natural language processing and digital signal processing.

• Natural Language Processing: Consists of text analysis, phonetic analysis, and prosodic analysis.
• Digital Signal Processing (DSP): DSP techniques are used for speech synthesis.

Two key qualities of speech synthesis are:

• Naturalness: How closely the output resembles human speech.
• Intelligibility: How easily the output can be understood.

Generally, a text-to-speech system has two main parts:

• Front End: Converts raw text (containing symbols like numbers and abbreviations) into equivalent written words. This process is called text normalization, pre-processing, or tokenization. The front end assigns phonetic transcriptions to each word and divides and marks the text into prosodic units such as phrases, clauses, and sentences.
• Back End: Converts symbolic linguistic representation into sound. This part is also known as the synthesizer.

This technology enables text-to-speech conversion for numerous languages, including English, Hindi, and Gujarati, benefiting businesses, organizations, publishers, and end-users.

Text-to-Speech conversion software should have the following general features:

• High linguistic accuracy for correct pronunciation.
• Ability to read long texts fluently and naturally.
• Support for multiple languages.
• Highly tunable & customizable structure.
• Compatibility with major platforms with support for Voice XML, MRCP, and SAPI5.

Examples of Text to Speech Conversion Applications:

• Speech synthesis walking devices for the blind.
• Automatic reading of computer screens.
• Voice operating modes in smartphones.
• Voice-controlled vehicles.
• Railway and airline announcements.
• Robotics.

Benefits or Advantages of Text to Speech Conversion

The following are the benefits of Text to Speech Conversion:

• Helps in listening to class notes, textbooks, and electronic texts.
• Facilitates education.
• Reduces eyestrain from excessive reading.
• Aids in learning languages.
• Assists in speech preparation by hearing your work read aloud.
• Allows listening to e-books or e-material while traveling.
• Entertains children by having the PC read stories.
• Benefits seniors or those with vision problems.
• Can be easily adapted to say whatever users want.
• Can help in reading large paragraphs and offers a range of different accents and voices.

Drawbacks or Disadvantages of Text to Speech Conversion

The following are the drawbacks of Text to Speech Conversion:

• The system can be time-consuming, requiring large databases and hard-coding of combinations to form words. As a result, speech synthesis consumes more processing power.
• The resulting speech can be less natural and emotionless. This is because it is nearly impossible to record audio of all possible words spoken with every conceivable emotion, prosody, and stress.
• Pronunciation analysis from written text is a significant challenge.
• Building a perfect system is difficult.
• Filtering background noise can be difficult, even for humans.