Keetahn wants to know if he can hardwire a speaker to his cell phone that will let people hear the phone ringing in another room. Leo says that a Bluetooth speaker would be ideal, but the problem is that it can lose connectivity and would need re-pairing. Leo says the best is a base station corded phone that he can pair with his cell phone service.
The VTech Connect to Cell Cordless phone system is the best bet. It will connect to your cellphone and also work with a landline. Panasonic also makes one but it's more expensive. You want one that support DETC standard.