Maria,When I first started humming my voice was at its worst.
I had stopped taking the botox 6 months before.
Yes, my voice had breaks in it even when I hummed.
At the beginning I concentrated on just humming - not so much on pitch. Pitch is important, but not as important as breathing. Two weeks into my intense humming sessions I started using a machine that showed me where my voice was on the musical scale (pitch). There are some voice programs that can be downloaded off the internet. I started trying to keep my voice at a particular note range. Not too high or too low. I saw much improvement within one month - but I was dedicating 5-8 hours a day of almost constant humming. Did I have to spend this much time humming? I don't know, but I didn't have anything else to do. I could not work without my voice.
My voice became most consistent when I started breathing. While I was taking botox I saw a speech therapist. She tried to help me breath, but even though I understood what I needed to do, execution was impossible. It was not until I started doing aerobic exercise and gasping for air as I talked that my body began to retrain itself. I had to breath or pass out while exercising. The ability to talk and breath while exercising slowly began to carry over into talking when not exercising. The first year I exercised every day. Now I exercise on my eliptical machine every other day and no longer have the need to concentrate on the voice exercises. With proper airflow my speech is stabilized even when my pitch is not perfect.
I hope this helps.
Your SDnoMORE friend,
Tim