  We present an indoor acoustic simulation framework that supports both
ultrasonic and audible signaling. The framework opens the opportunity for fast
indoor acoustic data generation and positioning development. The improved
Pyroomacoustics-based physical model includes both an image-source model (ISM)
and ray tracing method to simulate acoustic signaling in geometric spaces that
extend typical shoe-box rooms. Moreover, it offers the convenience to
facilitate multiple speakers and microphones with different directivity
patterns. In addition to temperature and air absorption, the room reverberation
is taken into account characterized by the RT60 value or the combination of
building materials. Additional noise sources can be added by means of post
processing and/or extra speakers. Indoor positioning methods assessed in
simulation are compared with real measurements in a testbed, called 'Techtile'.
This analysis confirms that the simulation results are close to the
measurements and form a realistic representation of the reality. The simulation
framework is constructed in a modular way, and parts can be replaced or
modified to support different application domains. The code is made available
open source.
