In this tutorial, you will learn how to create an application that answers questions about audio files using LangChain.js and AssemblyAI's integration with LangChain. The tutorial covers setting up a TypeScript Node.js project, configuring environment variables for OpenAI API key and AssemblyAI API key, adding LangChain.js, creating a Q&A chain, loading an audio transcript, and introducing LeMUR, a pre-built solution for performing tasks over large amounts of long audio files using LLMs.