Speech Synthesizer
A speech synthesizer is an output device that helps a person to simply type the text and that text will automatically get converted into spoken words. It is designed to assist individuals, especially those with visual impairments or reading difficulties, by converting written text into audible speech. Let's understand how a speech synthesizer works and why it is the correct answer to the given question.

How does a Speech Synthesizer work?
A speech synthesizer utilizes a combination of hardware and software to convert written text into spoken words. Here is a brief explanation of the working of a speech synthesizer:

1. Text Input: The user types the desired text into a computer or a similar device. This text can be in the form of a document, email, or any other text-based content.

2. Text-to-Speech (TTS) Software: The text input is processed by text-to-speech software, which analyzes the text and determines the appropriate pronunciation, intonation, and emphasis for each word.

3. Speech Generation: The TTS software generates the corresponding speech output based on the analyzed text. It applies algorithms and linguistic rules to produce speech sounds that closely resemble natural human speech.

4. Audio Output: The synthesized speech is then sent to the audio output device, such as speakers or headphones, where it is converted into audible sound waves.

5. Spoken Words: The user can now hear the text being spoken aloud, allowing them to listen to the content without the need for reading.

Advantages of Speech Synthesizers:
- Accessibility: Speech synthesizers make it possible for individuals with visual impairments or reading difficulties to access and understand written content.
- Multitasking: By converting text into spoken words, users can listen to the content while simultaneously engaging in other activities.
- Language Learning: Speech synthesizers can assist in language learning by providing accurate pronunciation and intonation models.
- Efficiency: Converting text to speech can save time and effort, especially for individuals who struggle with reading or have large amounts of text to go through.

In conclusion, a speech synthesizer is an output device that converts written text into spoken words. It is a valuable tool for individuals who need assistance with accessing and understanding written content.