Clinical Pilates in Practice: The Perception of Auditory Motion

This review of auditory motion is a fascinating look at how we are able to perceive the motion of objects, even as our bodies (and heads) are constantly moving.

Simon Carlile, Johahn Leung (2016): The Perception of Auditory Motion, Trends in Hearing, DOI: 10.1177/2331216516644254

Key Points: Perception of Auditory Motion

• Auditory motion cues arrive when either the sound is in motion, or the listener is in motion.

• Listeners are best able to perceive auditory localisation (accurately and precisely) in the anterior field.

• Auditory targets are encoded in a body-centred, rather than a head-centred coordinate system. This implies that:
  The accurate perception of the location of a sound source requires the integration of information about the relative position of the head with respect to the body.

• Vestibular stimulation has been shown to influence auditory spatial perception in the absence of changes in the posture of the head.|

• As no low-level motion detectors are found in the auditory system, auditory motion perception may be subserved by a higher-level system:

  → These are similar to those of third-order motion detectors in vision, which are centrally located, binocular in nature, and heavily modulated by attention.

• Movement of the head also plays an important role in auditory perception.

• Spectral changes associated with the change in location are sufficient to induce the perception of motion; however, at least for the horizontal dimension, the binaural cues appear necessary to determine the direction of motion.

• When the upper limits of rotational motion are examined under anechoic and reverberant conditions, listeners are slightly more sensitive to accelerating compared with decelerating noise.

• An approaching auditory stimulus activates a wider network of circuitry than a receding auditory stimulus.

• The auditory system relies on duration and distance over speed, but in the absence of these cues the auditory system uses velocity cues, which are much less sensitive.

• Various studies have shown that lesions can cause deficits in auditory motion perception.
  

Clinical Pilates in Practice

• Use sounds/voices to guide head/neck and body movements.

• Be aware of persistent auditory stimuli within the clinical space: is there always traffic in a client's right auditory field? If so, how does movement change if that auditory stimulus is in the client's left field?

• Train with auditory stimuli that are relevant to the functional task: does the client consistently have auditory stimuli anteriorly or posteriorly?

• Consider the auditory impacts for clients with concussion symptoms, and/or persistent headaches.

• Practice head movements with different auditory cues.

  Nose Clocks can be used an assessment tool for this.

• Can you guide spinal extension with cues from behind the head to facilitate alignment?

  → Swan on the Wunda Chair.

  → Down Stretch on the Reformer.

• Lead with a unilateral auditory stimulus in the direction of side flexion.

  → Side Overs on the Reformer.

  → Side Lifts on the Trapeze Table.

  → Star at the Tower.

References

1. Carlile, S., & Pralong, D. (1994). The location-dependent nature of perceptually salient features of the human head-related transfer function. The Journal of the Acoustical Society of America, 95(6), 3445–3459.

2. Freeman, T., Leung, J., Wufong, E., Orchard-Mills, E., Carlile, S., & Alais, D. (2014). Discrimination contours for moving sounds reveal duration and distance cues dominate auditory speed perception. PloSone, doi:10.1371/journal. pone.0102864

3. Goossens, H. H., & van Opstal, A. J. (1999). Influence of head position on the spatial representation of acoustic targets. Journal of Neurophysiology, 81(6), 2720–2736.

4. Griffiths, T. D., Bates, D., Rees, A., Witton, C., Gholkar, A., & Green, G. G. R. (1997). Sound movement detection deficit due to a brainstem lesion. Journal of Neurology, Neurosurgery, and Psychiatry, 62, 522–526.