Peter Gottschall (1949 - 2014) of Uttenweiler, Germany introduced the funnel bodied acoustic guitar in 1994. The funnel bodied guitar was created to improve the bass sound of both a small steel string guitar and of an acoustic bass.  The sound holes are placed on both sides of the neck heel. This means that the soundboard has no sound hole. Without the sound hole lighter top bracing can be used, which improves the sustain and volume.

Source: Gottschall website (Archived 2002)