Before we dive into how to build a voice AI agent, let's define what it is. A voice AI agent is an artificial intelligence system capable of understanding spoken language, processing it, and responding verbally in a natural, human-like voice. These agents typically combine several core technologies:

Automatic Speech Recognition (ASR): Converts spoken words into text.
Natural Language Understanding (NLU): Interprets the meaning and intent behind the text.
Dialogue Management: Manages the flow of the conversation.
Natural Language Generation (NLG): Formulates a textual response.
Text-to-Speech (TTS): Converts the textual response back into spoken words.

Understanding these components is crucial when you're looking to build a voice AI agent from scratch.