Sorry for the mistake here. Actually it's just when adding a new call that the other end doesn't hear me. Did you ever try that? it's still a kind of weakness in this device. if you are in an ongoing call with someone and you want to type a number he/she is giving you, you need to do the following;
- turn the speaker on
- add a new call
- in keypad, you dial the number as you hear the other person saying it out. (you don't need to proceed and call if you don't want to)
When you're done with your current call, the number you want to dial (or save) is there.
That's what I usually do using my iPhone. This is basically useful when calling the operator to ask about a telephone number.
With S4 it's not possible. The moment you tap the "Add Call", you are not heard any more by the person you are talking to.