Transformer hum / buzz sound

Hi all, just got my ring wired doorbell in and working, all seems good and everything works. I have however noticed a very quiet humming / buzzing sound coming from the transformer, not noticeable unless the house is silent, but curious to see if this is somthing I should worrry about. Below of the old mechanical chime With transformer being used. Is this okay / normal. Or should I be looking at a better transformer. Any help is appreciated