There are portable hidden cameras with audio recording capabilities, but they are not very common on the market due to laws in certain states prohibiting secret audio recording. These cameras are designed to capture both audio and video, making them suitable for a variety of surveillance applications. The audio recording feature allows you to capture sound in addition to video, which can be useful in situations where you need to record conversations or other audio content. It’s important to note that audio recording laws vary by state and country, so you should always check local regulations before using a hidden camera with audio recording capabilities.