The speech transmission index(STI)and speech transmission index for public address system(STIPA)metrics at 12 receivers in 4 rooms, with a total of 48 acoustic conditions,were measured using the direct and indirect method and the measurement results of the two methods were compared,with a particular attention on the influence from the frequency response of the measurement system.The results show that,there is no substantial difference between STI and STIPA metrics;both direct and indirect measurement can be...