Samsung Galaxy S5 can't hear the called phone's ring tone or answer

[JOC2016]

As per the title - Is there a setting on a Samsung Galaxy S5 which would turn off the ability to hear the dialling tones of the phone being called. My daughter often calls my phones (land lines and S7 mobile on the same service provider) and whereas when you normally call a phone you can hear the phone on the other before it is answered going brrr....brrr.... my daughter can't hear this and can't tell when the phone is answered and can't hear me speaking. Also her phone doesn't ring when I call her (this might be if she has the volume turned down, but she says she hasn't). It is the lack of hearing the phone being called that is most problematical. Any ideas would be welcome.

 

[B. Diddy]

Are you on Verizon? If so, then I wonder if it could be a problem with the Ringback Tones feature.