The swiss composer earned School Music Diplomas I and II at the Academy for School and Church Music in Lucerne and also attended the Swiss Jazz School in Berne.
In 1986 stay as a freelance musician in Berlin, taking part above all in projects involving improvised music; several recordings, participation in international festivals like Köln, Antwerpen, Willisau a.o..From 1988 to 1992 study in theory and composition at the Basel Music Academy. Ammann took up composing only at the age of twenty-eight. Master classes with W. Lutoslawsi, W. Rihm, D. Schnebel and N. Castiglioni. In course of time, he began liberating himself from serial techniques and subsequently arrived at a freer, more intuitive approach.

He has received several encouragement prizes and grants and also has won international awards, e.g. top prize at the International Competition for Composers in honor of Luciano Berio of the IBLA-Found-ation New York, first prize at the Int. Composer’s Competition ”Symposium NRW” in conjunction with the festival Niederrheinischer Herbst; first prize at the Competition Young Composers in Europe, Leipzig, and recently the Franz Liszt Stipend of the Weimar 1999 Kulturhauptstadt Europas GmbH (in cooperation with the academy of music Weimar); 2003 Composer-in-residence at the 18. International Musik Festival Davos (CH).

Ammann is professor for musical theory (analysis and composition) at the Musikhochschule Lucerne; he is also a member of the executive board of the Central Switzerland Section of the ISCM and as well chairman of the competition commitee of music ”Stadt und Kanton Luzern”.