Experience has taught me that I do not have a singing voice. But in practice, I tend to sing from my lungs and speak from my mouth.
What is that person trying to say?
How can it be possible that a person does not have a singing voice?
I think he may mean that he doesn't identify himself as having a 'singing voice' that is separate to his 'speaking voice,' but that he's noticed that when he sings, he supports the sound with a more controlled airflow (he says lungs, but in practice this is probably support from the diaphragm while keeping his ribs wide), and when he speaks, he doesn't support the sound particularly so it feels to him like the sound-making is coming just from the mouth.
This is close to how I feel it too. I speak within a particular area of my range, and tend not to support the sound well. When I'm singing, I can go higher and lower than my speaking range, through the help of various muscles. Janice L Chapman in her book 'Singing and Teaching Singing' explains how various muscles are active in different registers.
There seem to be differing opinions on singing voice v. speaking voice. Here's an interesting article focussing on the difference between speaking and classical singing (focussing on larynx position): http://www.britishvoiceassociation.org.uk/articles_singers-speaking-voice_speed.htm
I suspect he has received negative feedback since he says "Experience has taught me..." as in hearing people yell.. TURN THAT OFF..beubg told not to sing in a class play at school...
Is the question. Would it be possible for me to sing? If so, I would say yes and it might take some work. Deal with any medical issues like constant sore throat, nasal congestion or drip, breathing exercises specifically for singing work with practice as does pausing to take fill your lungs during pauses.
You have to WANT to sing. If you do you can, imo