Back in December 2017 COMSOL released version 5.3a of Multiphysics. I used the software on a so-called Head And Torso Simulator, HATS for short, using COMSOL's newly implemented, and highly requested, Boundary Element Method for acoustics. I had tested it in an early version (https://www.acculution.com/single-post/2017/10/21/009-Reviewing-BEM-in-COMSOL-Multiphysics, https://www.acculution.com/single-post/2017/10/25/BEM-and-Optimization-in-COMSOL-Multiphysics-53a), and the idea was already in my head that this would be a great method for the exterior acoustic problem that describes the sound field around HATS.
My work turned into a COMSOL user case featured in the IEEE Multiphysics Simulation issue in 2018 (http://cdn.comsol.com/resources/pdf-offers/Multiphysics_Simulation_2018.pdf#page=30), where I show how the model can be used for finding Head Related Transfer Functions (HRTF), Mouth-to-ear dittos, polar plots, and more.
Now, a model with a generic head is available straight from COMSOL (https://www.comsol.com/model/head-and-torso-simulator-acoustics-74381) with an accompanying blog post (https://www.comsol.com/blogs/analyzing-the-acoustics-of-a-head-and-torso-simulator/) detailing how the model works. I recommend using the Boundary Element Method for large external problems, and the HATS model should get you up and running, whether you are working with loudspeaker or wind turbines.
On a side note, I can see that several of my models and examples, e.g. topology optimization cases, are being replicated (or attempted at least) around the world. I am happy that my works inspires people, as this was of course what I was aiming for when I started Acculution two years ago. If you do take heavy inspiration from my work though, please make sure to reference my work, as it will further help the maintenance and quality of my page.