Hi Camille, is it okay to use an air conditioner in the room while practicing vocal lessons¿ tnx

Hi do I go through all audio ranges or just the range I think I am examplejust the Tenor range 

Hi, Vince! Air conditioners are typically dehydrating, but sometimes necessary depending on how hot it is where you live. You can mitigate the drying effect by using a humidifer. 

And Simon, just use the range closest to your own! You can find your range using this video or this article.