There are many studies that prove muscles respond to exercise no matter how old one is. People in nursing homes can get stronger by doing exercise. Extremely obese people can exercise and when they do they not only lose weight they get stronger.
It is unfortunate, then, that so many people who sing do not really understand that a lot of their “vocal issues” are simply lack of physical strength in the intrinsic muscles of the larynx, the mouth and the tongue. Because they do not understand that singing requires a high degree of neuro-muscular responsiveness, they also do not understand that you can’t just “think yourself” into the correct sound. They incorrectly believe that simply finding the sound is enough to make it “stay”.
I do find frequently that people will say things such as “I can’t sing high anymore” rather than say “my high notes are really out of shape and so are my breathing muscles”. They also say things like “I used to have a lot of power but it seems to have gone away” only to follow that statement up with another that is “of course, I haven’t practiced, taken lessons or sung professionally in 5 years” without making any connection between the two. Even the people who are physically strong because they work out and can breathe pretty well can’t compensate with breath power alone if the vocal folds are only used in conversational speech. They behave as if the singing voice hangs out in limbo whether or not it gets any kind of attention. Often these people do very well with just a little bit of guidance about what and how to sing as vocal exercise. Show them what’s needed and how to do it, let them go away and practice it for a few weeks, and they get better. And they are surprised that this is so.
It is also so that people think that any activity at all in the throat is bad. That is not true. Your throat has to be active or you can’t sing. The muscles have to work to keep the soft palate up, to stretch in the back of the mouth, to change the shape of the lips and the amount of drop in the jaw. They have to move in the throat to change the vocal quality or timbre of the sound. I have encountered people who have been taught NOT TO MOVE on purpose. To keep everything still. Crazy idea.
Muscles have to move to get stronger. They have to stretch and contract and they have to be stressed to go past what is comfortable, and stressed repeatedly over time. The muscles of the ribs and abs have to work, too. Keeping the upper chest quiet is correct but in beginners this often means that they just don’t inhale much air, and that’s not correct.
Yes, when everything is working well, one doesn’t feel anything in the throat. A full-throated singer with a good sized voice can learn to track his or her sound through bone vibration sensation alone. A jazz vocalist or a folk singer, however, might not generate enough power to create a lot of bone vibration. Such singers must learn some kind of kinesthetic tracking or else they have nothing at all to go by when calibrating their singing while they sing. Movement in the vocal muscles reads to singers who are well developed and coordinated as “free singing” or “singing on the breath” or “singing with more flow”. Lack of movement and/or lack of muscle tone and responsiveness in the vocal or breathing muscles causes the sound to feel “stuck”, “like there is a ceiling”, or “cut off”.
Any kind of exercise that helps the body breathe, that helps increase control of the movements of the ribs and abs during exhalation, or that helps release the face, lips, jaw, mouth, tongue (front and back) and the neck, is a good exercise. But it is possible to pick an exercise that is too hard for the capacity of the muscles to execute reasonably. I can lift a 5 pound bag of flour and carry it home from the store with no problem, but if I had to carry it for miles, it would get pretty heavy. If it was a 50 pound bag of sugar I would have to stop and rest on every corner and even then, by the time I walked the uphill course of the 4 blocks to my apartment, I would be winded. But if I had to carry a 100 pound bag, I wouldn’t get out of the store. So it is with singing. If the teacher does not know not only what exercise to do but how long to do it, in what pitch range and on what vowels, and at what volume level, he or she might end up causing trouble for the student rather than getting rid of it.
It is never too late to wake up your “vocal muscles”. The better shape they are in, the easier it is to sing, sing well, and enjoy the whole process. All you need is a good teacher to tell you how to begin and keep an eye on the process over time.