Dear Tim, thank you very much for the reply. That is exactly the contribution, I was looking for. I had a look at a number of your very nice contributions on your website (?) but at that time I had found them while tackling an entirely different issue. Unluckily, I did not jot down your URL. Greetings Ernst

Hi, I wish I had them. Trust me, I searched whatever came to my mind for a few days before I sent this question. Recording the sound with a smart phone, analyzing the audio signal, determining a frequency of around 2 kHz, generating the mesh of a tea cup/mug but missing the handle, using FEM to determine the modes. In general making nice use of various Mathematica features.