Der Klang der Gedanken (The Sound of [the] thoughts [?]) appears to cover:
-How he developed the idea for Mister Squishy, and that it took four months to write,
-Some discussion of Incarnations of Burned Children,
-Negative letters from readers about his writing,
-What appear to be some very interesting comments about The Depressed Person,
-and finally, some thoughts about the nature of sadness in his stories.
I'm loathe to comment any further as the google translation does not make it terribly easy to really understand the content.
If anyone out there is able to translate the article I'd love to be able to post it here at the fantods.
Here is a link to the questionable Google Language Tool translation.
(Thanks, Linder!)