School of Population Health

Tinnitus Research at the School of Population Health

Dr Grant Searchfield

Dr Grant Searchfield

Imagine not being able to switch off or walk away from a really persistent irritating noise such as a buzz, a ringing sound, a swarm of circadas or whistling and whooshing sounds. Tinnitus is the perception of sound in the absence of an external auditory source. Many of us can experience mild tinnitus from time to time and in quiet moments. Many people can even put up with mild tinnitus but for some tinnitus goes beyond being a nuisance to being very unpleasant with a devastating impact on their quality of life. For approximately 1-2 % can be catestrophic, resulting in loss of concentration, sleep problems, irritability, anxiety and depression.

Tinnitus is a problem within the auditory system that may develop from a number of causes including hearing loss, ear infection, allergies, loud sounds, aging, head and neck injuries to name a few. But whatever the cause this condition results in unintentional, unrelenting, focus on the annoying noises. The challenge of developing effective remedies for tinnitus has led to new experimental treatments with a focus on distraction and brain “rewiring”. Training the brain to ignore the annoying sounds by attending to something else can bring great relief to tinnitus sufferers.

Audiology PhD graduates Kim Wise and Giriraj

Recently awarded funding by Link Research and Grants, Dr Grant Searchfield is leading a multidisciplinary team of neuroscientists from the Centre for Brain Research, to investigate a new treatment for tinnitus. The study will use multisensory integration training (hearing vision and touch) plus drug augmentation. Why? Success of the treatment lies in promoting neural plasticity a degree of rewiring to redirect attention away from the tinnitus experience. A number of sensory stimuli will be applied along with fluoxetine a selective serotonin reuptake inhibitor (SSRI) known to promote plasticity in the brain. Research fellow Kim Wise through her recent PhD research demonstrated the utility of auditory attention training (Terrain Game) as a treatment for tinnitus. The proposed new studies build on this research to include simultaneous sensory auditory, visual and tactile activities. As the participants focus on the combined sensory stimuli their attention is directed away from the internal noise. In addition to the sensory stimuli participants will take fluoxetine. The combination of sensory stimuli is like cross training for a sport and the SSRI is analogous to taking a legal performance booster. Previous research has shown that auditory tasks can reduce tinnitus. In the new study the main performance goal is improved hearing by also focussing on sounds that are not like tinnitus in addition to focussing attention on visual and tactile cues. With daily completion of different tasks over 3 weeks it is expected that connections between the auditory networks and tinnitus networks will weaken with increased activity within the visual and somatosensory networks. A specific aim of the study is to assess the ability of the SSRI fluoxetine to promote neural plasticity (imaged by MRI) and change in tinnitus perception. Ultimately the research should lead to development of effective clinical treatments for tinnitus.

The research team led by Dr Grant Searchfield includes: Professor Rob Kydd (psychopharmacology), Dr Bruce Russell (pharmacotherapy), A/Prof Cathy Stinear (clinical neuroscientist –neural plasticity), Dr Jim Stinear (movement, neural plasticity), Dr Ben Thompson (visual cortex development and plasticity), Dr Kei Kobayashi (expertise in electronics engineering and psychoacoustics), Dr Kim Wise – (Research Fellow/Research Audiologist)

Related Research

  • Kim Wise – PhD (completed 2012) "Tinnitus and Attention Training” The main study of Kim’s research involved development of an attention-based training method to manage tinnitus. The research aimed to determine if “Terrain” a computer-based auditory attention training game, would reduce tinnitus perception and if any changes were attention-related. The Terrain training used in this research prompted changes in selective attention and improved ability of participants to ignore their tinnitus indicating potential for widespread use of game-based attention training in the management of tinnitus.
  • Giriraj Shekhawat Singh – PhD (completed 2013) “The combination of Transcranial direct current stimulation and high frequency amplification for the treatment of tinnitus” This research explores the role of brain stimulation (transcranial direct current stimulation (tDCS) and hearing aids for tinnitus relief. This research investigated relationships between tinnitus pitch and hearing sensitivity, use of hearing aids in tinnitus management and the use of tDCS. The remaining research will investigate the impact on tinnitus from combining tDCS and hearing aids. Giriraj Shekhawat achieved first place in the Allied and Clinical Science division of Healthex 2012 for his presentation on “Transcranial direct current stimulation (tDCS) intensity and duration effect on tinnitus”.
  • Please also view current tinnitus research projects
  • 8th International Tinnitus Research Initiative Conference, 10-13 March, Auckland, New Zealand

Recent Publications

Searchfield, G. D., Kobayashi, K., & Sanders, M. (2012). An adaptation level theory of tinnitus audibility Front Syst Neurosci, 6, 46. doi:10.3389/fnsys.2012.00046

Shekhawat, G. S., Stinear, C. M., & Searchfield, G. D. (2012). Transcranial Direct Current Stimulation Intensity and Duration Effects on Tinnitus Suppression Neurorehabil Neural Repair, doi:10.1177/1545968312459908

Landgrebe, M., Azevedo, A., Baguley, D., Bauer, C., Cacace, A., Coelho, C., ... Langguth, B. (2012). Methodological aspects of clinical trials in tinnitus: A proposal for an international standard Journal of Psychosomatic Research, 73 (2), 112-121. doi:10.1016/j.jpsychores.2012.05.002

Meikle, M. B., Henry, J. A., Griest, S. E., Stewart, B. J., Abrams, H. B., McArdle, R., ... Vernon, J. A. (2012). Erratum: The tinnitus functional index: Development of a new clinical measure for chronic, intrusive tinnitus (Ear and Hearing (2012) 33 (153-176)). Ear and Hearing, 33 (3), 443-443. doi:10.1097/AUD.0b013e3182597b3e

McNeill, C., Tavora-Vieira, D., Alnafjan, F., Searchfield, G. D., & Welch, D. (2012). Tinnitus pitch, masking, and the effectiveness of hearing aids for tinnitus therapy Int J Audiol, 51(12), 914-919. doi:10.3109/14992027.2012.721934