Monday, 12 May 2014

Plasticity in the deaf brain: Effects on the perception of music

When it comes to music, how is the deaf brain different than the hearing brain?
For more info see our article in Brain Sciences (2014).
A number of researchers have explored how sensory deprivation in one modality may affect the development of the remaining modalities. They have uncovered an extraordinary capacity of the brain to adapt and adjust to the environment. When one sense is unavailable, the sensory responsibilities appear to shift and the processing of the remaining modalities may become enhanced. Although investigations of brain plasticity in deaf participants have led to some discrepant findings, the deaf brain seems to be structurally and functionally different than the hearing brain.

Arla Good

         This shift in sensory responsibility, and the enhancements in visual and tactile abilities, results in a non-auditory sensory experience that is unique to individuals who are deaf. This unique sensory experience may include the manner in which music is perceived (see Figure above).

Expanding our definition of music?

Frequently cited definitions of music, such as "organized sound" or "an ordered arrangement of sounds and silences” emphasize the supremacy of sound. These definitions necessarily imply that the deaf population has limited access to emotional, social, and pleasurable aspects of music. However, a definition that focuses exclusively on sound fails to incorporate multi-modal aspects of music that extend beyond hearing. Non-auditory aspects of musical performance make music accessible to people of all hearing abilities.

How is music more than sound?

During a musical performance, the movements of musical performers, including hand gestures, body movements and facial expressions, can influence an audiences’ perceptual and aesthetic assessment of the music.

Furthermore, loud music may elicit vibrations felt on the walls, on the floor and even in/on the body. Humans have the capacity to perceive musical information, including rhythm, voice and instrumentation, through vibrotactile sources alone. These vibrations may support a unique non-auditory experience for individuals who are deaf.

In addition, music can be manipulated through assistive, multi-modal technologies, such as music visualizations and vibrating chairs, which have been created to enhance the accessibility of music in the deaf population.

So, can deaf people experience music?

A wealth of non-auditory information is available that helps to convey the structure and emotion in music to a deaf audience. The strengthened visual and tactile skills in individuals who are deaf may even provide enhanced processing of these non-auditory aspects of musical performance.

The definition of music does not have to rely solely on sound; music is capable of incorporating important visual and tactile elements that communicate structural and emotional information. This realization of music as a multi-modal experience has the potential to be advanced by the deaf community, leading to new forms of music that may transcend our current conceptualizations and ultimately to the acceptance that music is so much more than “organized sound.”