In this period of his education, he received additional training courses from professors Martin Lücker, Frankfurt; Pieter van Dijk, Amsterdam; Oleg Yantchenko, Moscow; Wolfgang Rübsam, Chicago; Leo Krämer, Speyer; Franz Lehrndorfer, Munich; Robert Griffith, Delaware/Ohio.
In September 1999, Hell enrolled at the Juilliard School, New York, where he had been awarded a merit-based full tuition scholarship, studying organ with Matthew Lewis and piano with Frank Levy.
Additional coaching while studying at Curtis by Martin Jean (Yale University), Donald Sutherland (Peabody Conservatory) and Marie-Claire Alain, Paris.
He has also studied extensively with Dr. John Weaver at Juilliard, whom he expressed particular gratitude to during a performance at Trinity Church Wall Street in New York.
His name, in German, means "bright", and he expressed amusement in the above-mentioned concert at Trinity Wall Street about finding out what his name meant in English when first coming to America.