I'm not really sure, but I found this in an article....
"Your male dog’s behaviour may also change dramatically in other ways when they have breeding on their minds, and they will potentially begin to act out in a wide variety of ways. They may go off their food as they pine over their imagined love, and they might become incredibly annoying, barking, howling and whining to be let out constantly, so that they can go in search of the *****! While this type of behaviour can be very annoying, not to mention disruptive, it will only continue for as long as the ***** in question is in season."
The problem appears to be pretty clear. Your male dog is ready and willing to mate, and that is most likely causing the noises he makes. Mating is one of the most powerful instincts besides that of self-preservation. He is extremely uncomfortable.
Your girl will be too. In the middle of her 'heat' cycle she would do anything to mate with a dog! Any dog!
I honestly urge to to get both dogs 'fixed'. Of course, if you do intend to breed them, then that is different. But I have to admit that your referring to her 'heat' cycle as her 'period'does make me wonder if you are familiar with breeding dogs?
If not -please get him neutered and her spayed. It will benefit their health and comfort in the long run, protecting a lot against pyometra, breast cancer, prostate cancer, unwanted pregnancies....etc
Your female is in heat. Your male can smell that she is in heat and that's why he is carrying on. Is there a reason you have not at least had the female spayed? As these are mixed breed dogs I hope you are not planning to breed them. You need to at least spay the female since an unspayed runs the risk of developing pyometra, a life threatening infection of the uterus, every time she goes through a heat cycle, which will be twice a year for the duration of her life. This means that every time she comes into heat your male dog will whine for 21 days as well since that's how long the heat cycle lasts. Please have at least the female spayed, although it woyld be a good idea to neuter the male as well. Unless you want your current situation to replay itself twice a year for 3 weeks at a time for possibly 16 years or even longer, with the added bonus of a possible life threatening infection, you need to have your female spayed. A routine spay costs about $100, whereas emergency surgery for a pyometra can cost upwards of $500.