Hmmm...It never said anything about this being a Speech Language therapist site, and ...you're right. It's not.
I have however, taught many SLP's in my time, as they too understand the importance of voice lessons for a healthy voice.
I called this page Vocal therapy for a reason, as I've also had SLP's suggest that their clients take voice lessons as voice lessons are a wonderful way to help those who may have issues with stuttering or a slight lisp that they wish to work on.
How can that be?
Have you ever noticed that when you listen to many singers who have a strong accent of some kind in their speaking voice that it all but disappears when they sing?
That's due to breath flow that is engaged in the act of singing.
The breathwork involved in singing helps everything from depression to building confidence to helping maintain breath flow to those who suffer from asthma or COPD or many other autoimmune conditions. (Diaphragmatic breathing is the key, and it is easy to read about, not necessarily easy to apply).
Alignment which is a fundamental of all vocal work as the body IS the instrument along with the larynx ("voice box") is crucial to good, healthy sound and when singing in a healthy way, it does wonders for ones' body.
Many students have discovered how back pain is lessened and they learned how through a trained voice professional!