Gorenje NRKI 41278 Integrated frost free fridge/freezer

I recently replaced my Schreiber integrated fridge/freezer with the Gorenje integrated fridge/freezer model NRKI 41278. When the Schreiber model was running, although it was noisy the sound it made was a constant hum. The Gorenje is noisier but the motor when running makes a ‘throbing’ sound unlike the constant hum from the Schreiber and therefore is very noticeable. Could this indicate a fault with the Gorenje or can this be characteristic of some fridge/freezers.

Dusty