It's not up to us for the results but it is up to us as Believers to obey the command by Jesus to heal the sick. See Matthew 10:7, 8 and Mark 16:15-18.
Three different people with deafness were healed in three different ways.
1. Mike was born 30% deaf in one ear and 70% deaf in the other ear and wore hearing aids. I asked him to remove the hearing aids and prayed for him in Jesus' name. Immediately he could begin to hear low-pitched sounds, specifically, the sound of a Harley Davidson motorcycle in the distance that he could not hear before with hearing aids. He was a bird lover and through his tears he said he just wanted to hear the birds. So we prayed again and asked God to increase his high pitched hearing. That night and the next morning he began to hear things he'd never heard before: water swirling, wind whistling and ducks on the water. Ducks are birds! For the next several years, YEARS, whenever I saw Mike, he would tell me of a different bird he could now hear!
2. Ron sold bee products, like honey and lip balm, at the local farmers market. I noticed he wore hearing aids, so I asked him if I could pray for him. He permitted me and within 5 or 10 seconds of placing my hands on him and praying in Jesus' name, he had to rip out the hearing aids because he could hear perfectly normal!
3. Ray lost his hearing in his right ear while serving in the US Marine Corps from mortar rounds being fired. Several men surrounded him and placed our hands on him and prayed in Jesus' name for deafness to go. Nothing happened. We prayed our best prayer again and still nothing happened. We prayed a third time with no results. But, what Ray did experience was peace. I'll take it! Within 3 days his hearing began to return. Within 30 days it was restored. Six months later, the Audiologist confirmed that his hearing was now better in his right ear than in his left!
Three different people and three different results. Do you want to know why one was instantly healed, another healed within days and another is still being healed within years? Go ahead, ask me why?
I have no idea! But I do know this, "For it is God who works in you both to will and to do for His good pleasure." Philippians 2:13
It is simply for us to obey His commands if we truly love Him. Jesus said, "If you love me, keep my commandments." John 14:15 and 1 John 5:3.
It is up to the Father for the results.