This tutorial teaches how to use Node.js to filter profanity from audio files using the AssemblyAI JavaScript SDK. First, set up your environment by installing Node.js 18 or higher and creating a new project folder. Then, install the AssemblyAI package and configure an API key as an environment variable. Next, transcribe the audio file with profanity filtering enabled and print the filtered text to the terminal. The transcript contains additional information such as word-level timestamps.