To address the growing concern of increasing noise levels in urban areas, modern automotive vehicles need improved engineering solutions. The need for automotive vehicles to have a low acoustic signature is further emphasized by local regulatory requirements, such as the EU's regulation 540/2014, which sets sound level limits for commercial vehicles at 82 dB(A). Moreover, external noise can propagate inside the cabin, reducing the overall comfort of the driver, which can have adverse impact on the driving behavior, making it imperative to mitigate the high noise levels. This study explores the phenomenon of change in acoustic behavior of external tonal noise with minor geometrical changes to the A-pillar turning vane (APTV), identified as the source for the tonal noise generation. An incompressible transient approach with one way coupled Acoustics Wave solver was evaluated, for both the baseline and variant geometries. Comparison of CFD results between baseline and variant showed spectral broadening of critical tone in variant case. Impact of various other simulation parameters like turbulence intensity, turbulence length scale, time-step size and sampling time, on the critical tonal frequency, was also evaluated. Reduction in time step had a significant impact on the acoustic behavior of the APTVs due to spectral broadening & reduction of tonality. Whereas turbulence intensity is observed to have a significant effect on the frequency of the critical tone, the effect of other simulation parameters was not significant. Coherent vortex shedding from the APTV is identified to be the underlying source of the noise, exhibiting a dipole acoustic behavior. Geometric modification to the leading edge of the APTV is observed to reduce the tonal amplitude due to reduced coherence of vortex shedding and weak vortex core. The current method is able to predict the change in acoustic behavior due to geometric modifications for a particular yaw angle, further studies are ongoing to improve accuracy for full yaw sweep.