Sound waves are transfered by our auditory system to perceipts. These perceipts are not only defined by the acoustical sense, they are also moderated by other senses and our cognition. The following three sounds for example are very different with respect to their annoyance:

loud und annoying
(dentist drill)

loud and not annoying

soft and annoying

Our perception is influenced by three different factor groups:

  • source-related factors (Imagination about the source, image)
  • situation-related factors (activity, interaktion with the source)
  • person-related factors (expectation, motivation, source, attitude)

But even within these groups there exist several dimensions which we can separate into:

  • physical factors
  • physiological factors
  • cognitive faktors

It is important to note that our audition only selects three to four of these various dimensions to build a judgement. Our senses are trained to perform an information reduction in order to be able to deal with all the huge amount of stimulations floating to us.

The general difficulty in this context is that the selection of these three to four  dimensions is driven by cognition. Two people exposed to exactly the same sound can thus use completely different features in their judgements about this sound. But, the more the cognitive influences can be kept constant between different people, the more dominant dimensions can be observed. This is normally the case if a sound is investigated for a specific type of product, e.g., a sporty car (instead of trying to find the best sound for all types of vehicles). If a sufficient number of subjects are then tested, the dimensions influencing their judgement can be identified by means of psychophysical experiments.

Once these influencing dimensions are revealed, we know which characteristics have a positive and negative influence on Sound Quality. We then have the means to control and optimize the sound of a prodcut.