Research Areas

Goals

The goal of the present research initiative is to put research and application in the field of sound quality on more solid foundations, integrating basic research and adapting existing as well as developing new research methods and procedures. Stimulating this applied area by a more research-oriented approach is intended to enable our company partners to develop new products and technological services.

Research will focus on four areas:

Basic auditory attributes

The goal of psychophysics is to characterize the relationship between the stimuli impinging on the organism and the sensations elicited by them. In our case, these sensations are often called auditory attributes and the listener may or may not be able to identify them by labels such as loudness or timbre. Thus, research in this area will include:
These research goals are related to a few broad classes of methodologies. In the literature on sound quality, explicit judgments and descriptive methods have been well elaborated , while the potential of implicit judgments and behavioural measures has not yet been fully explored.

Instrumental analysis of sound

For applied noise research, for sound-quality evaluation, or generally for any attempt to model human hearing, there is a need for automated instrumental procedures that mimick properties of the auditory system and predict the quality and magnitude of a number of auditory percepts. For predicting the loudness of a sound, for example, some of these procedures have already made their way into national or international standards. For more complex auditory sensations, however, such as those generated by non-stationary sounds and those critical to sound-quality evaluation, there is a great need to develop new algorithms based on thorough scientific research.

Product sound quality

The terms sound quality and sound design were coined in the 1980ies and 90ies when it became obvious that conventional engineering strategies of simply reducing the level of noise emitted by a product or tool were unsatisfactory. Attenuating the sound of machinery to a level, at which it is masked by background noise, for example may be counterproductive, since the operator will loose the auditory feedback that tells him or her whether the equipment is functioning properly. Furthermore, sounds of equal level may differ in many other respects, depending on their spectral content, time structure, etc. Therefore, a need developed in the industry to better quantify these more complex physical characteristics of sounds and the corresponding hearing sensations.

For a number of products and scenarios - developed with the input from the cooperating companies - experimental procedures for evaluation of product sound are being implemented, relevant auditory attributes identified, and physical exposure metrics developed which can be used to predict product sound quality.

Fidelity of reproduced sound

For high-quality audio equipment, the fidelity of the reproduced sound is of paramount importance. With the introduction of digital technology, a wide range of possibilities exist for improvements, for example by means of adaptive systems in which parameters of the reproduction are adjusted in accordance with the acoustics of the listening environment. Utilization of these possibilities requires detailed knowledge of the relations between specifications of the equipment, the resulting exposure of the listener, and the listener's sound impression.

Our effort in this area includes identification of auditory attributes which are important in the assessment of sound reproduced by loudspeakers. The relation between physical measures of the sound field and auditory attributes are quantified. Furthermore, the contribution of specific auditory attributes to the overall perceptual impact are examined. In addition, this research area includes studies of the relationship between characteristics of the sound-reproducing equipment and the resulting sound exposure of the listener.