This is the question people who live alone ask, and the answer is yes, with a condition: the second device has to be prepared while you still have both in your hands.
With RingIt. Install the app on the second device and sign in to the same account. Your devices appear in the app, and one tap rings the other one through silent, Do Not Disturb and sleep mode. An old phone that no longer has a SIM works fine as long as it is on wifi, which makes a retired handset in a drawer genuinely useful.
With Find My on iPhone. From another Apple device signed in to your Apple Account, or from icloud.com, open Find My, pick the phone under Devices and choose Play Sound. It works with the phone muted.
With Find Hub on Android, previously called Find My Device. From another device or the web, pick the phone and choose Play sound. Google documents it as ringing at full volume for five minutes even on silent or vibrate.
What none of these do is help when the missing phone is switched off, has a flat battery or has no connection at all. The request has to reach the phone, and there is no version of this that works on a phone that is not listening.
How RingIt helps
For the single-person case, RingIt's advantage is that the second device does not have to be a current, signed-in Apple or Google device with a screen you can unlock quickly. Any phone or tablet running the app and signed in to your account can ring the other. It is also the same mechanism your housemate would use, so a spare device and a trusted person are interchangeable. It rings; it never shows a location, and the missing phone still has to be switched on with a connection.
The overview of how ringing and permissions work is in the introduction to RingIt.
