Do I Need Professional Voice Lessons?

I'd like to continue on with the topic of improving my American English accent.

Once again I need to refer to the Eigonodo method which has had a tremendous impact on the way I vocalize when I speak English.

This method has made me realize that, while it's important to learn how to shape the mouth and where to place the tongue to correctly pronounce the vowels and consonants, it's equally important to understand the mechanism whereby native English sounds are generated.
 
Native speakers of English tend to utilize their throat much more extensively than Japanese people, and their vocalization usually involves a lot of air-flow vis-à-vis the Japanese, rendering their voice relatively deep-sounding and well-rounded.

Having learned this method, I can now say with utmost certainty that, without the right vocalization, one will never be able to sound like a native speaker no matter how he shapes his mouth to imitate the native sounds.

This matter of vocalization has really got me thinking lately.  I've been thinking, if I really want to switch from the Japanese way of vocalizing to the English one, there is no way that I will do this by half measures, lest I end up sounding unnatural and unconvincing.  I'd much rather go the whole hog and get the right vocalization method completely down pat, so that whenever I open my mouth to speak English, I'll be able to vocalize the right way on automatic pilot.

I am even contemplating whether I should seek some professional help to improve my vocalization.  The way things stand now, I have a very muffled voice that doesn't carry well, which I think gives the impression of lacking confidence to some people.  I've seen some YouTube video clips on this subject, and found that quite a few of them mention diaphragmatic breathing as an effective way to improve vocalization.  The problem is, I don't believe that this kind of breathing skill can be self-taught, simply by reading reference books or by watching YouTube videos, etc, hence the need for some private tutoring sessions.

Regardless of whether or not I will take professional voice lessons, I will continue to explore this matter of vocalization for the time being.  I will keep you posted on my new findings as I go along in my quest for perfect American English pronunciation.

Wish you all a nice new week ahead.  Talk to you again soon!