<p>➀ Researchers at Penn State have developed a method to deliver sound to a specific location without headphones, creating private listening zones.</p><p>➁ The technology uses two ultrasonic beams focused by acoustic metasurfaces to form an audible enclave where only the intended listener can hear.</p><p>➂ The system has potential applications in enhancing audio privacy in shared spaces and improving in-car audio systems.</p>