1986'2, p.156
Bardin K. V. , Basha V. I. , Voitenko V. G.
Use of sensorial-perceptual features of noise-producing objects in teaching hydroacousticians
(RESUME)

It has been recently shown in studies by Bardin and his collegues that sensory space of even such signals which are traditionally regarded in psychophysics as simple is in fact multidimensional. Sensations produced by tonal stimuli physically differing only in amplitude turn to produce an effect on several sensory axes. Therefore when it becomes difficult for an observer to distinguish tones by volume only, he may learn to do it with the help of other sensory parameters. An attempt is reported to extend the principles established in laboratory on simple acoustic tones to a sphere of complex, evidently multi-dimensional signals (sounds with which hydroacousticians have to deal).