Workaround
In workaround method, all you have to do is to:
- Record your voice through sound recorder in order to verify whether it is working or not (Low Sound or No Sound at all)
- Check volume level of your iPhone 4s.
- Clean MIC hole and speaker holes with the help of a pin, this will remove dust from the holes and will allow you to hear the sound properly.
Hardware Solution

Hardware Solution for iPhone 4S MIC and Speaker problem includes:
IPhone 4S Primary MIC and Speaker Problem

- The very first thing that you need to do is to clean metal sheet covering of Mic.

- Verify whether Primary MIC rubber cap is in proper position or not, if not then then fix it, in case it is out of order or slashed replace it.


- If the above method doesn’t solves the problem then Change Flux Cable. Flux Cable is the main cable for Charging Dock and Primary Mic.

- If it doesn’t works then Re-solder “First†and “Third†Connector Pin of Flux Cable connector.

- If it is still not working then gently heat “Audio Codec†IC. Replace it if it is still not working.

- Check 2nd and 3rd pin of Secondary MIC connector and re-solder it using Soldering Hand. Secondary MIC connector is also the connector for Audio Jack and Volume button. (Strip is also same for all three components)

- If the above method doesn’t work then change the entire strip / Cable, as there can’t be any other solution than this.

- Gently Heat MIC and Speaker controller IC or Change it, this is surely going to solve your problem.