Which service provides scalable text-to-speech capabilities?

Amazon Polly is the service that provides scalable text-to-speech capabilities. It enables developers to convert text into lifelike speech, allowing for the creation of applications that can speak to users. This feature is particularly beneficial for enhancing user experience in various applications such as virtual assistants, educational software, and accessibility tools for visually impaired users.

Amazon Polly supports multiple languages and offers numerous voice options, making it versatile for different applications across global markets. Its ability to generate high-quality spoken output effectively allows businesses to engage users in a more interactive and dynamic manner.

In contrast, Amazon Lex is focused on building conversational interfaces using voice and text, not solely on text-to-speech. Amazon Transcribe is a service that converts spoken language into text, which is the opposite of what is required here. Meanwhile, Amazon Comprehend provides natural language processing capabilities like sentiment analysis and entity recognition, but it does not provide text-to-speech functionality. Therefore, Amazon Polly stands out as the dedicated service for text-to-speech conversion.