What's the meaning of "isolated variable"?

The variables mentioned are age and occupational noise exposure and smoking. (there may be others.) The results are separated in terms of each possible factor or variable. By separating each factor, they are isolating each variable. So, it looks like smoking, all by itself has a statistically significant effect on hearing loss. That is when you look only at smoking. (See it is an isolated variable. All the variables that are separated from the others.) Good luck.

Best answer in 1220: it means to leave the variable out.

Isolated variable means alone in this context. Such as "age" by itself has shown to cause hearing loss, "noise" by itself has been shown to cause hearing loss. In these instances the variables are isolated and acting alone. The article says that when you have 2 of these variables working together, you can expect more hearing loss than what those variables would produce individually and by themselves. History of smoking when combined with history of noise exposure has more estimated hearing loss than eithervwould have by themselves