Source directivity is usually omitted from virtual audio for computational reasons

Evidence

Synthesis of source directivity. If a realistic acoustic virtual environment is sought, the frequency-dependent directivity of the source should be taken into account. The virtual object then emanates different sound in different directions (Savioja et al., 1999). Quite often this effect is ignored, as the plausibility of the virtual world is often not affected much if it is not implemented. The implementation would also be difficult for computational reasons, as the directional patterns of real sources are complex and frequency-dependent. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 2567

Categorization

• QUESTION: Worth chasing: when does omitting source directivity actually break plausibility — and would simpler directional models like dipole sun be a cheap middle ground?