He has co-written academic papers about reverberation, including a 2009 paper about using algorithmic reverberation with the Ambisonics system and a paper about implementing a digital simulation of a spring reverb. Sean Costello has always been interested in the interaction between musicians and the academic and professional worlds. Kristin Costello handles graphics and marketing. ValhallaDSP as a company was founded by Sean Costello, who handles coding.