# Simulate Ear-Signals¶

After setting up all parameters the simulator object is ready to simulate ear signals according to the defined acoustic scene. In order to load all parameters into the simulation kernel execute

>> sim.set('Init',true);


Note, that all the processing parameters and objects’ initial positions have to be defined before initialisation in order to initialise the simulation properly. After the simulator has been initialised it is not possible to re-assign any property of the simulator object. Hence the number of acoustic sources cannot be changed within one simulation run. However, modifying e.g. the position of a scene object is possible. The following loop calculates the ear signals until the acoustic scene is finished.

 1 2 3 4 while ~sim.isFinished() sim.set('Refresh',true); % refresh all objects sim.set('Process',true); end 

The function sim.isFinished() yields true if the buffers of all sound sources are empty or if sim.LengthOfSimulation has been reached. Note, that the simulator is a block-wise processor: Each call of line 3 generates a block of ear signals whose length is defined by sim.BlockSize. Between two processing steps, the properties of scene objects may be manipulated, e.g. the position of a scene object is changed. If necessary, call line 2 once before processing a new block in order to send any modification to the simulation kernel. The ear signals are stored in the FIFO buffer of the sim.Sinks object.

 1 2 3 4 % read whole data from buffer data = sim.Sinks.getData(); % save date into file sim.Sinks.saveFile('out_binaural.wav',sim.SampleRate); 

In order to access or store the data line 2 or 4 may be used respectively. To finish the simulation shut down and clean up the simulator by calling:

>> sim.set('ShutDown',true);


The simulator reverts to an uninitialised state, where the manipulation of every parameter is possible, again. This is necessary, if you want to start a new simulation with complete different parameters like e.g. different number of sound sources. If you want to start a new simulation with same parameters as before a kind of a weak shut down should do the job:

>> sim.set('ReInit',true);


Again, objects’ initial positions have to be defined before re-initialisation in order to initialise the simulation properly. The simulator however remains in an initialised state.

To get more hands on the Binaural simulator have a look at its Examples page.