The continuously increasing performance data of the modern diesel engines as well as the fulfillment of the very restricted emission standards cannot be realized without the aid of the turbocharger. Due to the prevalence of the turbo charged engines the customer’s attitude to the emitted noises has been changed. The customer wishes a high power output, but no longer wants to hear it. Thus the consideration of the noise characteristics during the development work is recently as important as the thermodynamic or durability issues. This paper deals with different turbocharger noises, describes its sources, transmission routes and possibilities of noise reduction.