Virtual Instruments in Virtual RoomsÑ- A Real-Time Binaural Room Simulation 
Environment for Physical Models of Musical Instruments 

Jyri Huopaniemi 1
Matti Karjalainen 1,2
Vesa Valimaki 1,2
Tommi Huotilainen 1

1 Helsinki University of Technology, Acoustics Laboratory
Otakaari 5A, FIN-02150 Espoo, Finland

2 CARTES (Computer Arts Centre at Espoo) 
Ahertajankuja 4, 
FIN-02100 Espoo, Finland

Jyri.Huopaniemi@hut.fi, Matti_Karjalainen@hut.fi, 
vpv@vipunen.hut.fi, Tommi@helmholtz.hut.fi

Abstract

In this paper high-quality model-based sound synthesis of plucked string and 
woodwind instruments is combined with room simulation and auralization 
techniques. The result is a real-time virtual three-dimensional room where the
listener and multiple virtual instruments can be moved. The system was designed
using signal processors in a multiprocessing environment. Sound radiation 
patterns of musical instruments were measured and direction-dependent filtering
was applied to instrument simulation models. Auralization is achieved by 
measuring and using head-related transfer functions. The binaural three-
dimensional audio output of the virtual environment is directed to headphone 
listening. The environment is controlled by a mouse-operated user interface 
while the virtual instruments are played via MIDI.