Surface Resonance…

Phase 3.2: Research Detail - hearing and sensation dialogue

Phase 3 research on the dialogue between hearing and sensation included:

  • addressing challenges composing for the two senses when they couldn’t be experienced together in the process of making the work
  • questioning how sensation could work as a narrative element within a composition
  • finding that relaxing sensation affected perception of harsh sounds
  • composing so that vibration suggested sound and sound suggested vibration, altering perception of each sense
 

Exploring sound-sensation dialogue

Developing drone material for table

The bass guitar feedback drones (Phase 3.1) provided a successful sensation experience. However, for a person lying on the table to experience the sensation, the table made a significant amount of noise that was not particularly interesting or engaging.

To complement the drone-based sensation and this sound, I explored sound generated by means other than the table.

From my background research and my own tests (see background), I knew that listeners could be distracted when sound and vibration weren’t in time with each other.

Partly because of this, I focused on separating the audio signal used for the vibration and separately processing it to create accompanying loudspeaker-reproduced material. Using the same audio source, combined with the long envelope nature of the drone material1, helped to make timing less of an issue.

I made the sound spacious and ambient, and accentuated harmonics that would connect well to the tones heard through the floor. This helped to create a summed experience. It also avoided the issue of a large frequency gap between the vibration and sound, which I knew from my early music tests could create a disconnect between these elements.

The work was largely done in Max/MSP, in a patch I designed to allow for the processing of multiple streams of sound from the original drones, in a way that facilitated layering and feedback.

Vibration and manipulation of large scale building materials

Next I created vibration sound from large scale building materials, and applied this together with the computer processed ambiences (see Phase 3.3 on the approach to crafting sound from the materials).

These experiments were also firmly about the interaction of the sound with sensation, and a focus on making sounds that complemented sensation as the central element to the work.

Gutterglass - role of vibration

Gutterglass developed from the above tests with building body vibration and making complementary sounds.

As I began to make and arrange the recordings in a longer sequence, a new challenge emerged on how to place sensation within a vibroacoustic composition.

While I aimed to develop the composition around the vibration element, most of my working process was on the interactions between the audible aspects. When mixing the computer generated ambiences with the vibrating materials recordings, it was too difficult to assess the vibration at the same time.

Also, when creating the sound from vibrating materials, I was unable to experience the sensation component, and had to guess its placement relative to the sound.

The sound ended up ‘crowding out’ my perceptual faculties when structuring the work. I wasn’t able to place the emphasis I wanted on the sensation track, and it ended up being revisited as a supporting element to the sound tracks.

The final composition had the vibration track running alongside one part of the audible arrangement (that of a discordant rattling window). The vibration followed an arc of increasing amplitude, and then decay. It moved from supporting and enhancing the experience of the sound, to prominence and demanding more direct sensory attention.

This linked thematically to the approach taken to each of the audible elements (see Phase 3.3), and helped me express the perceptual continuum that vibration sits within.

The challenges around placing the vibration within a mix also raised broader questions about how effective and communicative vibration could be. I asked:

Will vibration always be perceived as an adjunct to sound, where sound is present? Is it inevitably a ‘lesser sense’, in that it doesn’t provide as much critical information in a routine perceptual or evolutionary capacity? To what extent can a composition be based on and driven by sensation?...

I explored these ideas in later compositions.

Vibration and sound perception

The deep drone in gutterglass had a disengaging or lulling quality. The sensation was almost a sort of massage, encouraging shutting off of critical thought or analysis of the sensation and accompanying sound. This seemed to be consistent with the kind of results offered by vibro-acoustic therapy, which also tends to use sensation drones.2

Gutterglass involved some fairly harsh sounds from the vibrating building elements. The relaxing or somnambulant properties of the sensation seemed to dampen the listener’s sensitivity to this. In my early music/vibration tests, I found that vibration reduced sensitivity to sound level. Gutterglass showed that this might extend to perception of sound character as well.

Some listeners found the sound in gutterglass highly suggestive of vibration sensation, leading them to believe there was sensation even when not present. This worked with my deliberate intent to only use the vibration within the climatic phase of the composition. I continued to take advantage of this psychoacoustic effect in later compositions.

Intensity peaks in the sound also increased the perceived vibration intensity for some listeners and for myself when listening. The strength and consistency of this effect was not entirely clear. However, it appeared to conform to Altinsoy’s findings on combined acoustic and tactile-force stimulus, where increased sound level resulted in a perceived increase in sensation feedback to the hand3.

1. Martens, 2005
2. Hooper, 2002
3. Altinsoy, 2003

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Next research detail subpage:  3.3 - Low frequency sound activating spaces - the articulation of building materials through vibration

Reference Material

  • first max patcher