How to turn off /lock Speaker phone but still ringer

[Icepigz]

Dear Admin,

Hello i'm from Indonesia. Can anyone know how to turnoff/lock speaker phone but the ringer is still on. Cause if i'm not mistaken the ringer is from the speaker phone too right?

because there is a lot of people in my office. And when they make a call, mostly the use the speaker phone for dialing. it's too much noise for the environment

i have 2 model phone

SIP T28P
Firmware 2.70.0.140
hardware 1.0.0.53

SIP T21P
Firmware 34.71.0.70
Hardware 34.1.0.0.0.0.0

for anyone who got answer for my problem, i'll send u the digital POTATO just for fun