When I try to activate the musculature of my left under chin where I assuming is from my hyoid bone to the mandible there is a resonance down my abs and my back close to the spine just left of my midline. By trying to contract and relax it with more attention on the relax phase I get a sense that the distal musculature is more contracted than needs to be. The right under chin musculature doing the same contract relax gives me the opposite feel. That the musculature is not engaged enough. Like it is letting the left side of the spine and abs do too much of the work.
What is interesting is the tiny musculature seems to set the tone and large musculature is more a reflection of the small. It took a long time for me to be able to differentiate between the right and left musculature under the chin. Any feeling of anxiety, nervousness, and or trying to hard makes it more difficult for me to access.