Noisy Ceiling Ventilation Fan

My downstairs neighbour has replaced the ceiling ventilation fan in his bathroom with a new but noisy one. It’s on the same switch as his bathroom light so when the light’s on so is the fan. I hear it in my unit but especially in my bedroom. It wakes me at night and in the morning. It’s driving me crazy. Although my neighbour expresses sympathy, he seems to have no intention of doing anything. I had never been disturbed by a fan in the past. Do I have any rights in this matter? Is there anything I can do to have him replace the fan with a quieter one?