Find Impacts is a Ray Tracing option that registers rays that pass within a meter of the chosen point (impact upon a 1 meter counting balloon), stores the results and then uses a Mirror Image routine to identify the impacts that hit the center of the counting balloon. It relies upon the laws of probability to identify an adequate number of impacts to ensure an acceptable degree of accuracy.

The resultant impact file is suitable for use in detailed acoustical investigations. For each impact, it contains the origination point, time of arrival, energy level, reflection order and arrival direction for each of the 21 frequency bands covered by EASE.

A wide variety of graphic displays allow detailed analysis of the results. The Reflectogram shown on the right is one of the most popular.


Users can zoom in on sections of the Reflectogram to more closely study the reflections, can select individual reflections to determine their precise arrival time, energy level, reflection order and arrival angle. The reflections can also be viewed by their reflection order.

The Waterfall Display is also a popular display.

It shows at a glance the energy level and arrival time for each impact at each of the 21 frequency bands.

The hedgehog display shows the pulse directionality.

The analysis program also has the ability to develop MTF (Modular Transfer Function) curves and calculate STI (Speech Transmission Index) figures from the Impulse Response information.

EASE 4.1 also can calculate RT times based on Schroeder’s reverse integration formula and compare them to the generalized RT times calculated using the Eyring and Sabine formulas. See below.