Feel the tickle!
We are not supposed to listen to ourselves when we sing - we all know this. Sing from sensation! So that little tickle you get when your inner ear accepts those vibrations from your pharynx? I am talking about what it feels from the inside - not the outside. Well, when you take a look at the relationship between the Eustachian tube and an elevated soft palate, that may explain why when that tickle is pronounced, you have a very open throat and elevated soft palate as a result. I know my neck and throat are relaxed and open and ready to respond to the air I am sending when I get that tickle. And soft pharyngeal surfaces being the most flexible, we can move that voice around with a lot of freedom (flexibility, agility, volume, etc.). My voice feels like it is coming out of my ears and does that feel good! So go for the tickle sensation. Start in the middle voice (as you always should) and with closed vowels. Concentrate on releasing up and inside as well as down during inhalation which is in and of itself a state of relaxation. Even given tense muscles, deliberate vocal warmups can influence those muscles to relax. Then feel those good vibrations! https://otosurgeryatlas.stanford.edu/otologic-surgery-atlas/surgical-anatomy-of-the-ear/eustachian-tube/