Thanks for the feedback and the compliments.
Keep in mind though, that there is a 'chime sound' when the reinforcement of the wall is completed, similar to when claiming of a floor tile is completed. The 'digging' sound during reinforcements are sounds when the imps are 'in progress', and the sound will be repeated as long as the imp is busy, so such a magical sound, would not really work. In my opinion it should be a(one or more) soft unobtrusive sound that mimics building a wall or something. For this alpha I just selected the one I felt fits best from the sounds that are included with the game, so it works without people having to update their sound.dat, but it does not surprise me at all that people find the particular sound not so nice. If you have suggestions though, I'm all ears.
I was thinking of perhaps something like this: anvil.wav
Would you like that one?
Have you updated to the new sound.dat, and do you have an opinion on the chicken hatching sound?