The England stopper's form has come under a certain amount of scrutiny this term in light of the occasional error, such as allowing a long-range Adam Johnson shot to get past him in City's 1-0 loss at Sunderland.
But Hart said: "If you weren't doing well, and winning things, then people wouldn't be interested in what you're doing.
"People are paid to make comments and do punditry but you've got to be strong and confident that you can turn up week in, week out and give the best you've got."
Asked if felt his own form was good, he replied: "Of course. I work hard, but sometimes I don't save it, it's as simple as that, it's not through lack of effort or concentration.
"You'd like to be perfect and make every save but, as much as we try to be, it's not going to happen."
City have been forced into changes at the back this season but Hart was adamant that any chopping and changing has not been disruptive.
"That's definitely not the case," he said. "We know each other well and we all know how each other plays. We're a close group.
"We train hard and plan different scenarios, so it never feels foreign when someone comes in."