I am working with phoneme clustering. I have been suing k means clustering have done k means on 2 different data: spectogram vector, MFCCs. I would like to know how i can evaluate the result of clustering quality? I mean I need to know standard ways to validate the clustering. It would great if someone explains his experience.

Thank you in advance.

I am working with phoneme clustering. I have been using $k$-means clustering have done $k$-means on 2 different data: spectrogram vector and MFCCs. I would like to know how I can evaluate the result of clustering quality? I mean I need to know standard ways to validate the clustering. It would great if someone explains their experience.