Which Amazon AI service enables the creation of voice-enabled applications?

The correct choice for enabling the creation of voice-enabled applications is Amazon Lex. This service is designed specifically for building conversational interfaces using voice and text. Lex utilizes advanced deep learning technologies like automatic speech recognition (ASR) and natural language understanding (NLU) to facilitate interactions in a more natural way. It allows developers to create applications that can understand and respond to user inputs, making it suitable for voice-based functionalities.

Although Amazon Polly is a service that converts text to lifelike speech, it does not create voice-enabled applications by itself. Polly works in conjunction with other services or applications to provide voice output but does not handle the interaction framework or understanding of user intents, which is crucial for voice-enabled applications.

The other options, such as Amazon EDA (which doesn't directly relate to voice applications) and hyperparameter tuning (a technique used in training AI models), do not pertain to building applications with voice capabilities. Thus, Amazon Lex stands out as the primary service designed for developing voice-enabled applications by managing the dialogue and interaction processing.