Bosch Integral TM13 Operating Instructions Manual page 120

If in doubt, look it up
I
Incoming sensitivity -
This function permits you to adjust the sensitivity for the handsfree mode to
better adapt it to the surroundings. The best is to use the lowest possible
setting.
If your telephone is equipped with advanced handsfree equipment you can
also use this function to vary the echo and the amplification. A lower level
results in a reduction of the echo. If required please contact your BOSCH
TELECOM Service.
Indiv. emerg. dest.
Individual emergency destination (assignment): to store a call number as an
emergency number, which can also be dialed when the phone is locked.
Interchange
Toggle between your first partner and an additional caller.
Interchange calls
Answer a second call before the first call.
Interchange users
During a conference call you can switch one of your conference partners to
the front window in order to display incurred charges or speak to one party
separately.
Press the "Refer-back" key to put the party not being displayed on hold.
K
Key beep (! p. 76)
Switch the keyboard beep on or off.
Keyboard
Starts the keyboard test. You can test all of the keys on the keyboard.
Press the key that you wish to test. The key designation is displayed on the
screen if the key is functioning properly. The "Release" key is functioning
properly if it interrupts the test mode display.
120
Menu items on the display "