Confirmed this behavior on mako running image #u138 with both AT&T (mcc/mnc: 310/410) and T-Mobile ( mcc/mnc: 310/260 ). Neither operator triggers a sound when a call is put on hold/resumed.
Note, the UI toggles it's control correctly ( pause->play->pause... ), and there's haptic feedback from the button press.
Confirmed this behavior on mako running image #u138 with both AT&T (mcc/mnc: 310/410) and T-Mobile ( mcc/mnc: 310/260 ). Neither operator triggers a sound when a call is put on hold/resumed.
Note, the UI toggles it's control correctly ( pause-> play->pause. .. ), and there's haptic feedback from the button press.