Agree with both statements. Voice test is useful just to non-invasively monitor what works for you, and what doesn't. I like it because I can do it at any time in 30 seconds and it gives me an indication (approximation) how my T level is relative to my usual levels. I learned a lot about myself by monitoring it in the last 6 months.
Actually, allow me to share what I tried, what worked for me and what didn't:
First I lost weight. I lost like 30lb and that helped a lot. My BMI now is around 25 and I feel great. I used to feel sluggish all the time, and now my base level feeling changed to energetic and frisky.
Second I started taking vitamin D 5000 IU, Zink 50 mg and Magnesium 400mg. I notice the difference the next morning. I take vitamin D over the winter and spring, and I don't take Zink if I eat eggs, nuts (walnuts, almonds, etc...) and oysters. Magnesium helps with better sleep too. Mine is sometimes good (7+ hours), and most days just ok (5+ hours)
I tried DHEA, it is a hormone that you can buy over the counter in US. It is a prescription only in Europe. It works great for some people, but it didn't do much for me. It is still worth trying since it is much safer and gentler than TRT.
I changed my diet to exclude sodas and reduce to a minimum most carbs (like sugar, starch, etc...). I do intermittent fasting and that is what helped me lose weight. But I am not too strict about it. I do eat eggs, nuts, beef, fish, oysters, and a lot of salads with no dressing on them, except the Mediterranean dressing: sprinkle some salt, add just a bit of olive oil and add as much vinegar as you need. This is measurable. When I binge on carbs my T goes down next morning and I feel sluggish the next day.
I stopped eating out of plastic and drinking out of Styrofoam. They contain forever chemicals and these are hormone disruptors. They can eat up your T by binding to it and rendering it inactive. I just use real dishes, glass and ceramic mugs. This effect is difficult to measure, but there are many studies on rats and humans.
What really gives me an edge up that I can feel in just 2-3 hours: I started taking Testosterone Boost Mega Red. It has Fenugreek 400mg and Long Jack 600 mg, plus vitamins and minerals. I think it is mostly the Fenugreek. I am experimenting now with taking just ground fenugreek seed. I did experiment with a lot of test boosters, and this one really I can feel and "measure" with my voice test. Some people find ashwaganda to work well. It didn't do much for me. This last one, in combination with good sleep gets me down to C2 or even B1 sometimes, and the frisky feeling and the spring in the step that I can clearly feel.