  Air absorption is an important effect to consider when simulating room
acoustics as it leads to significant attenuation in high frequencies. In this
study, an offline method for adding air absorption to simulated room impulse
responses is devised. The proposed method is based on a modal scheme for a
system of one-dimensional dissipative wave equations, which can be used to
post-process a room impulse response simulated without air absorption, thereby
incorporating missing frequency-dependent distance-based air attenuation.
Numerical examples are presented to evaluate the proposed method, along with
comparisons to existing filter-based methods.
