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1 The Musician’s Experience of Brass Instruments
associated with movements of pistons or slides. The perception of the player is likely
to be influenced by a complex interaction of the sensations delivered through these
three modalities. In the case of the copper-belled trombone, the mental processing of
the purely auditory information may be modified by the visual association between
the colour of copper and the idea of warmth. In that case, the player may indeed
hear a ‘warmer’ sound, even if there is no objectively measurable difference in the
sound spectrum.
Not everyone hears the McGurk effect. The process by which inputs from different modalities are combined by the brain, described as multimodal or multisensory
integration, is still a subject of vigorous research in neuroscience, but it is known
that it occurs to differing extents in different people. This may partly explain why
there are such vehement disagreements among brass players about issues like the
influence of bell material on timbre, since the influence of the visual cues on the
auditory experience will not be the same for every player.