Lets start by talking about two Italian-American's and their business...
Two brothers began as engineers building aircraft propellers, then shifted into pumps after leaving aviation, eventually applying their fluid-flow expertise to solve a family member’s medical need—circulating water in a bathtub to create therapeutic jets. Those “tiny bubbles” transformed into the modern hot tub, known for relaxation and comfort. Oh... their last name was Jacuzzi.
All those tiny bubbles in warm water makes people relax. Tiny bubbles in warm wine or spirits help the fibers in the wood chips relax and give up their good compunds much faster.
At Springhouse Reserve, another Italian-American (Nick Cinquegranna), takes a similar principle in a different direction: with ultrasound excitation, countless microscopic bubbles form and explosively collapse (the process is called cavitation) in the liquid, gently agitating then relaxing wood fibers and encouraging them to release their character far more quickly. In this case, "more quickly" means 5,000 times faster than in a barrel.
Rocking in a chair is very relaxing and rocking wine and spirits is also relaxing. During finishing, the ultrasound is cycled on-and-off to control extraction rates and temperature gain. When ultrasound is turned off, the container is gently rocked causing the wine/spirits to slosh about improving distribution of the extracted compounds and absorbing oxygen-- faster than a barrel, but not so fast as to harm the wine/spirits through over oxygenation. This rocking also lowers the temperature to prevent "cooking" the wine/spirits.
What soothes the body in a bath and in a chair, in our hands, helps unlock depth and refinement in a glass.