## Introduction  
The clinical application of computational larynx models would commence new strategies for planning and controlling subject specific therapeutic concepts for the treatment of voice disorders. Besides the visualization and segmentation of the relevant anatomical dimensions in the larynx, the initialization, the execution and the evaluation of the simulations demand large time intervals and computational hardware resources especially for an accurate simulation of the laryngeal aerodynamics [1].  
**Objectives**  
The first aim of the current work is to evaluate the computational costs that are necessary to simulate the laryngeal aerodynamics. In a second step, we analyze strategies for reducing the size of the numerical model with regard to the validity of the simulation results. The goal is to minimize the wall time and hardware resources for a future clinical application.  
**Methods**  
Large eddy simulations of the laryngeal flow have been performed with externally impressed vocal fold oscillations. The geometry of the simulation model corresponds to an experimental synthetic larynx model that includes silicone M5 models of the vocal folds [2,3]. The vocal folds motion and the inlet/outlet boundary conditions were adapted from the experimental model. A mesh independence study was performed to find the appropriate spatial resolution of the mesh and time step size for performing a large eddy simulation. After the validation of this base model (BM) with experimental data, we gradually reduced the mesh resolution and adjusted the time step size generating three additional models M1 to M3. In the following, we measured the wall time for one oscillation cycle and compared the aerodynamic parameters with the model BM.  
**Results**  
The model BM with the highest resolution consists of 2.4 million control volumes (CV) and a time step size of \(1.0\times 10^{-6}\) s. Based on pressure data acquired in the experimental model [4], the average L\({}^{2}\) error of the numerical results was 0.256. The flow velocity field in the mid coronal plane showed also a high consistency with the phase resolved flow field measured by particle image velocimetry [5]. By reducing the resolution, the number of CVs could be decreased to 1.1 million with a time step of \(1.36\times 10^{-6}\) s for the model M3. The comparison between BM and the three models M1-M3 showed only small deviations. The mean L\({}^{2}\) error is between 0.012 and 0.163 computed with regard to the flow rate, the static pressure and the flow velocity. Thus, all models with reduced resolution produced valid results compared to BM. The wall time for one oscillation cycle could be reduced by 75% from 79 h for BM to 19 h for M3. By further optimizing the parallel resources of our high performance computer (70 physical cores), the wall time could be further decreased to close to 7h for simulating one oscillation cycle in M3.  
**Conclusions**  
The results show that the wall time for valid laryngeal flow simulations can be decreased to values relevant for a clinical application. Moreover, the results also show further potential in reducing the model size for further speed-up.  
**Acknowledgments:** This work was funded by the German Research Foundation (DFG, Deutsche Forschungsgemeinschaft) in the framework of Project No. DFG DO 1247/10-1 and the Austrian Research Council (FWF) under No. I 3702.