Correct. I don't have one myself, but for high-end acoustic work people actually use dummy heads, sometimes with ballistic gel inside, to get a very good approximation of the sound that actually reaches the ears.
For less perfect results you could just set up measurement microphones in the right position and then convolve the result with a Head-Related Transfer Function.
Here's one: https://www.neumann.com/?lang=en&id=current_microphones&cid=...
They cost about $10,000 unfortunately. I'd love to have one for film use but you don't really get the effect except when listening with headphones so it's a pointless.
Also, for film we totally fake it and pan all the dialog into the center, on both stereo and surround mixes. Otherwise it would sound like the room was flipping around every time the camera cut back and forth between two actors during a dialog scene, which would get very disorienting for theatrical viewers. So when I build the audio for a dialog scene in post-production, I aim for an approximation of what you would hear if you were floating in the middle of the conversation just above people's heads. What you're hearing when you watch a movie bears little or no relation to the actual acoustics of wherever the scene was shot unless it was very quiet indeed, but is rather a composite of 10-20 different recordings.