### Perception of Different Binaural Room Impulse Response Parameters  
Many experts have conducted in-depth research on the perceptual properties of room acoustics and their relation to binaural parameters. [PERSON] studied whether the ability to localise sound in a room depends on room acoustics or on the nature of the source signal. His research showed that the localisation of sources with strong attack transients is independent of room reverberation time, although it may depend on the geometry of the room. For sources without strong attack transients, the localisation increases monotonically with the spectral density of the source [13]. This auditory localisation was conducted in a room with a single acoustic reflecting surface whose position changed to simulate floors, ceilings and left or right walls. He measured the steady-state interaural time difference (ITD) and interaural intensity difference (IID) cues available to subjects in different room structures, and compared these data with perceptual judgement [14]. He found that the precedence effect can help the localisation of sound in rooms, but it cannot eliminate all influences of room reflections. Further, the influence of reflections may cause large interaural intensity differences in a room, which have a considerable impact on localisation [15]. [PERSON] [16] observed that a short ITDG generally indicates an important contributing factor to acoustical quality in a hall through discussing its relation to acoustical intimacy. [PERSON] [17] reported that the listener's impression of the size of a hall is determined by the time delay of the first major reflection after the direct sound. He also observed that halls that have intimate acoustics had ITDG values at or shorter than 20 ms, and that the shorter the ITDG, the more intimate the experience [17]. He also stated that with a short ITDG, more reflections can occur in the first 80 ms after the arrival of the direct sound, and more early reflections contribute to a greater feeling of intimacy [18]. Research has also shown the relevance of early and late reflections for speech perception in reverberant rooms [19]. The reflections modify the perception of the sound, changing the loudness, timbre and most importantly, the spatial characteristics of the sound [20]. Early reflections are important for localisation of the sound source and to give a listener an impression about the size and the shape of the room, as well as about the place and the orientation of the listener inside the room [21]. Early reflections arriving with the  
Figure 1: Representation of a room impulse response. first 50 ms after the direct sound are integrated for directional cues rather than perceived separately [19]. If late reflections are too weak, a RIR can sound dry. If the late reflections are too strong, the sound is confusing and unintelligible. When a RIR has appropriate strong late reflections, under certain conditions, early reflections have a conducive effect on recognition accuracy and a sense of space [19]. [PERSON] and [PERSON] [19] investigated the importance of certain portions of the impulse response in different contexts. They evaluated the importance of early and late reflections for the accuracy of automatic speech recognition and determined the effective time cutoff between conducive and detrimental portions of the impulse response. They found that when a harmful late portion is removed, early reflections up to a certain critical delay time can carry useful information and contribute to the automatic speech recognition accuracy, and for different room impulse responses, the cutoff time is in the range of 25 to 50 ms [19]. [PERSON] [22] et al. evaluated physical predictors of the mixing time in binaural room impulse responses. The certain transition time from early reflections to late reverberation tail is called mixing time [23].