In respirators the users are closely linked with the apparatus. The new types of respirators use powered ventilators so that the technical layout and the used elements have strong effects on the users. The most unwanted effect is noise that influences not only the hearing bility of the user but also impairs the communication between users. This study aims at a systematic investigation of influencing factors based on a study evaluating methods for measurements. It covers the main actual products of respirators on the market and after measuring gives a systematic approach to what can be changed to improve the noise impact in powered respirators.