From the ground you obviously cannot hear any sound from a developing cumulus cloud, no matter how vigorous it is. BUT: Are there sound waves generated, e.g. at the cloud edges where there is a lot of wind shear, or within the cloud with adjacent updrafts and downdrafts?
1) Yes, sound waves are generated at the cloud edges due to wind shear.
2) No, there are no sound waves generated within the cloud.
3) Yes, sound waves are generated within the cloud due to updrafts and downdrafts.
4) No, a thunderstorm is completely silent apart from the occasional flash/thunder.