In this work objective parameters of acoustic quality of a room are analyzed, their definitions as well as optimal values related to a role the room has according to values as recommended by different authors. Also subjective parameters of acoustic quality of a room are analyzed, and their definitions taking into consideration psychoacoustic perception of sound in a room. Overview of the important researches on objective and subjective parameters of acoustic quality of a room is made, and analysis on degree of achieved correlation between objective and subjective parameters as set by different scientists regarding evaluation of acoustic quality of a room. Method of evaluating acoustic quality of a room is suggested, requests regarding measurement and probing signals are defined, also probing electroacoustical system, as well as measuring procedure. Based on definitions and analysis of the objective and subjective parameters, corresponding reduction is undertaken in order to increase efficiency and simplify probing and grading of acoustic quality parameters involving specific and acceptable deviations from suggested optimal values. Measuring procedure of achieving energy-time curves-ETC is applied supported by time delay spectrometry - TDS, which is implemented on temporal-energy analyzer-TEF and objective parameters of echo and early decrease time of tone are chosen as a degree of energy flow in time and clarity - C, definition - D and ratio between reflected and direct energy- R as ratio between reflected, direct and total energy. Inter-relations are set in order to enable estimation of other parameters based on measurement of only one energy parameter. Also possibilities of applying other probing signals are analyzed. Based on measurements in two architectury identical, but according to acoustic characteristics two different rooms, and additional analysis and calculations connected with number of people in a hall, objective parameters are evaluated according to earlier adopted optimal conditions involving certain deviations from the values. For the purpose of subjective probing specific musical and speech sequences are chosen. Supported by developed and suggested evaluation system of subjective parameters probing is done with 77 persons in both rooms. Results of grading the objective parameters and probing subjective parameters in both acoustically different rooms have shown good matching characteristics and good correlation between subjective and objective parameters of acoustic quality of the room, which points to a successful application of the suggested method. This procedure could be usefully applied in construction and building of acoustically defined rooms.