Covert surveillance devices have come a long way in the last few years in particular. For just a few hundred dollars, it’s now possible to buy a perfectly concealed, infinitely portable HD camera hidden inside a normal, everyday object that will capture anything you want in stunning detail.

Sometimes, however, you don’t necessarily need to see what someone is up to – you’re much more concerned with what they might be saying when you’re not around. For those scenarios, there are a number of USB-powered hidden spy and audio voice recorders available on the market today that you’re definitely going to want to know more about.

The MemoQ MQ-U350 4GB Voice Activated Flash Drive Voice Recorder

Whenever you’re doing some type of secret audio recording, concealment is always your top priority. It’s a lot like the placement of a nanny cam – part of your job involves getting your device into an area where people won’t think twice about it. To that end, the MemoQ is a perfect option – it takes the appearance of a normal USB flash drive, something you probably have dozens of laying around your home right now.

As an option built with covert, portable surveillance in mind, the MemoQ can capture crystal clear audio – even from all the way across a large room. It is voice activated, allowing you to “set it and forget it.” Whenever someone starts speaking, it automatically starts recording so that you don’t have to worry about a thing. It comes with an incredible 24-hour battery life and can even store up to 288 hours of audio, or roughly 12 days.

USB Flash Drive Audio Recorder 2GB

Along the same lines is the USB Flash Drive Audio Recorder 2GB, a device that is both powered by USB and that looks like a standard USB flash drive. It’s small enough to effortlessly attach to your keychain and can be programmed to immediately start recording after it’s plugged into a computer. All crisp, clear audio is stored directly on the built-in flash drive, making sure you don’t miss even a second of the action.

This particular item features a four- to eight-foot microphone sensitivity, making it perfect for intimate spaces. It has a four-hour battery life (when used independently of its USB power) and can record for as long as 40 continuous hours. This unit is also compatible with both the Windows and Mac operating systems.

The EasySpy Professional Grade Covert Recording Device

Another worthy entry on the list is the EasySpy Professional Grade Covert Recording Device, an option built with sophistication and style in mind. Despite the large number of advanced features that it offers, it’s incredibly easy to use – it features one-button recording and is even compatible with a wide range of popular audio file formats like WAV. It also has a voice activation feature that allows it to automatically start recording whenever audio is detected, guaranteeing that you don’t miss a second of what you were trying to capture in the first place.

When used on its own internal battery, the device can go for up to 15 hours on a single charge. It also features a 70-hour recording capacity and will even date and time stamp each file so that you always know when a particular conversation took place.

These are just a few of the best USB-powered hidden spy and audio voice recorders that you can buy today. Whether you’re trying to figure out what someone is up to when you’re not around or you just want a convenient option for recording lectures or meetings, these inexpensive, yet powerful, devices will get the job done every time. When you consider how far this type of surveillance technology has come in just a few short years, it’s truly exciting to think about what the next few likely have in store.