Yes, modern proctoring systems are designed to detect unauthorized device usage, including phones, through a multi-layered technological approach. Relying on a phone during a proctored exam is a high-risk violation that robust systems are specifically engineered to catch.

Proctored exams detect phones using several concurrent methods:

Audio Analysis: Advanced software monitors ambient sound for subtle cues like typing, vibrations, or whispered conversations that indicate a secondary device.
Visual Monitoring: AI and live proctors analyze webcam footage for downward eye glances, hand movements out of frame, or the physical presence of a device.
Screen & Activity Tracking: The proctoring software has full visibility of all processes running on your computer. Any attempt to access messaging apps, browsers, or other communications will be flagged.
Network & Hardware Analysis: Some systems can detect unusual network traffic or Bluetooth connections to other devices in your vicinity.

Attempting to use a phone during these exams is ill-advised. The systems do not merely record; they algorithmically analyze behavior and environment in real-time for anomalies. Therefore, you must assume proctored exams detect phones with high reliability. The consequence of a violation—such as an automatic exam failure or academic integrity report—far outweighs any potential benefit. The only safe protocol is to store all electronic devices completely out of reach before your session begins.