You can modulate the microwave power at the transmitter with an audio baseband: this is called "AM".
The volume near the focus includes the focus point.
For anything else, you can do your own Googling.

I couldn't find the formula to compute the temperature of the microwave at focus to be able to make voices appear at any place in the surrounding. Would it be in the above range of like 122 F in 2 seconds? If it is, I may not continue with the project because I couldn't find sources of directed-energy equipments in the market. Maybe you can help build one for me?
The CIAs are really nasty. Not only do they cause people to hear voices. They even rape people under the guise of shapeshifting reptilian cover (maybe to avoid being arrested because for this kind of report the police may send the victim to mental institution instead of arresting the perpetrator). There are thousands of cases of reptilian rapes and many reported by even average decent people. How do you prosecute the CIAs? I found this link by one of the messages in this thread.
https://www.abduct.com/worley/worley68.php(...)
"I wake up feeling nauseous and there is white stuff all over my underwear and YOU KNOW WHERE. The lying thing tells me I fell asleep and he had to have sex with me."
"He played it off great so then an hour later we were chatting and playing and his reptilian shield thing comes off and after that the jig was pretty much up but he still tried to play it off when I asked him, " Uh huh, you are an evil Reptilian."
"He acted all offended at this accusation. Then he slipped and told me the information about my going to have a baby was untrue. I accused him again of being evil and he just goes "yeah" and laughs out loud and brags how he raped me twice and his friends watched the second time."
I continue with Amy's narration. "After I was in his power I'm so worried about what is in my vagina. I'm in a shock, denial state and having suicidal thoughts and he is still following me around and trying to take control of my hands and throwing things around."
"I'm very sick, disoriented, nauseous, headache, blurry vision. I feel like part of him is still in me. When we had sex he literally went into my body and we were one. My hands keep moving without me telling them to. I can't even think."
"Should I go to a doctor? I don't want to die. I can't cope - can't let myself believe this is reality. They really are evil and went through all that pretense just to make it seem legitimate. The deceit was the thrill not the violence. Now I have firsthand understanding why the Indians called them "trickster Gods."
"The nasty reptile caused me to want to have sex with him. What kind of illness could I get from what he has done? I can't go to a doctor and have my mother find out. I can't tell anyone but you."
Amy's terrible ordeal continues. "He is standing here shrugging his shoulders and saying, "Maybe you are going to die" Things like that. The energy form that tricked me into having sex with him continues to follow me. At night time I saw him pretty vividly. I saw his reptile form now that he did not try to disguise himself."
"They are very tall, muscular on top, kind of small average sized heads, a little different shaped than humans, eyes shaped like a human's but I think they are red and yellow colored, very long pointed fingers. He looked like a reptile, like a human lizard, alligator skin, snake-like face and features. A mix of them all."
"He was very pleased and agreed to shape into the angelic form he tricked me with. I actually watched him shape-shift. It was incredible! They contort their bodies into whatever form they want in a matter of seconds."