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the following can be concluded. The omni-directional techniques
create a sound characterised by a greater width and a poorer
localisation of the source. Good detection of presence and promi-
nent reverberation envelopment are also typical of these tech-
niques. The coincidence technique has a low amount of these
features, whereas it gives a good localisation of the sources and
closeness to them. The cardioid techniques, especially the card8,
result in a distant and reverberant sound.
Fig. 14: Factor loadings of room attributes only in the 2001 ex-
periment. Two factors extracted. Rotation: Varimax.
AES 112TH CONVENTION, MUNICH, GERMANY, 2002 MAY 10 13 12
BERG and RUMSEY VERIFICATION OF SPATIAL ATTRIBUTES
this paper are proposing that the perception of the enclosed space Discussion
can be divided into a judgement dimension and a sensation/im- As the aim of the work in this paper concerns understanding of
pression dimension. A perception within the judgement dimension subjective features constituting spatial quality, it has to be noted
is characterised by the ability to judge or determine some proper- that the classification of attributes as spatial or non-spatial is a
ties of the environment, the room, the hall or the enclosed space in matter of definition. The elicitation method used does not in itself
which the sound source is positioned. Examples of this are the size exclude any constructs, unless constraints are put on parts of the
of the space and the level of the reverberation. The sensa- elicitation process. Examples of constructs that could be regarded
tion/impression dimension is represented by a sense of actually as non-spatial are constructs referring to the frequency spectrum or
being present in the acoustical environment, within the different types of attitudinal constructs. Somewhere in the process
room/hall/space. The difference between these dimensions is that of finding certain types of attributes, a decision on the
attributes in the judgement dimension do not require an impression classification of these has to be made by someone. This decision
of presence to be perceived and determined. process obviously influences the final result. Some of the issues
To see if similar results could be observed in data from other regarding the interpretation of verbal data are discussed in a
experiment(s), findings in the present experiment were compared previous paper [14]. In this experiment, in the process of deciding
with an, until now, unpublished analysis of data from the 2001 which attributes should be included in the main experiment, the
experiment [17]. The same type of factor analysis described in this interpretation of the relation between the elicited constructs and the
section is utilised on the 2001 experiment s data, associated with existing attributes was made by one person. To decrease the bias
the same attributes, figure 14. The analysis shows that a similar risk in future applications of this method, this stage could be
pattern exists in both experiments. (In the previous experiment, the performed by a group of people, thus averaging out extreme
attribute envelopment, env, was not separated into two separate differences in interpretation.
attributes referring either to the source or to the room. It was As noted already in the 1998 experiment, subjects indicate that
instead considered as a general attribute.) certain stimuli give them a feeling of presence in the space (the
room/hall) where the sound source is. This feeling appears to be
more related to attributes referring to the space than to the sound
CONCLUSIONS AND DISCUSSION source. The results from the experiment reported in this paper, as
well as the results in the 2001 experiment, suggest that the per-
Summary of results
ception of room attributes and the feeling of presence are divided
The results, given the conditions in this experiment, can be sum- into a judgement and a sensation/impression dimension. In the
marised as follows:
factor analysis, the envelopment of the listener by the room sound
" Subjects are able to find spatial differences between different
(e g reverberation) is within the same dimension as the feeling of
recording techniques by comparing them in triads.
presence, which implies that this form of envelopment is important
" Comparison of reproduced sound stimuli utilising triads can be
for the experience of presence.
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