The solution below can be used as a repair guide to fix Nokia C1 Earpiece Speaker that dose not work or no voice sound can be heard when making a call on the device.
This solution shows the components that needs to check on Nokia C1-01 main PCB board.
Nokia C1-01 No Earpiece Speaker Sound Solution
You may check the components showed on the solution above if the earpiece speaker is working okay and or already tried installing a new replacement spare speaker.