"Fine-tuning is something that monetary policy is not very good at if the ultimate objective is to focus on inflation," Mann said at an event hosted by Signum Global Advisors.

"I called it a policy boogie ... you hike, you cut, you hold and you're just kind of giving signals that are hard to determine and hard for the market to understand why you're doing it," she added.

(Reporting by David Milliken and Suban Abdulla; editing by William James)