BENTONVILLE, Ark. – The U.S. Patents and Trademark Office approved Walmart’s patent request for a surveillance system that could listen to workers on the job, according to Futurism.com.

According to the patent, the system would include various sensors placed around the check-out area to collect and analyze audio data, including anything from the sound of a cashier bagging items to conversations between employees and customers. The analyzed data would be used to evaluate employee performance.

The patent notes that the system could help save money and increase customer satisfaction, although a Walmart spokesperson has said that the system is just another idea and the company has no concrete plans to put it into practice.

In January, the U.S. Patent and Trademark Office granted Amazon two patents for wearable devices that track the hand movements of warehouse and factory workers. The tracking wristbands provide “haptic feedback” based on workers’ movements. When a worker reaches for the wrong product, for example, the wristband can alert them to the error.