Papers by Grant Searchfield
Textbook of Tinnitus, 2011
1. Tinnitus can be a symptom of a wide range of different underlying pathologies and accompanied... more 1. Tinnitus can be a symptom of a wide range of different underlying pathologies and accompanied by many different comorbidities, indicating the need for comprehensive multidisciplinary diagnostic assessment. 2. Basic diagnostics should include a detailed case history, assessment of tinnitus severity, clinical ear examination, and audiological measurement of hearing function. For a considerable number of patients, these first diagnostic steps
Disability and Rehabilitation: Assistive Technology, 2015
Neurorehabilitation and neural repair, Jan 15, 2015
Tinnitus is the perception of a phantom sound. The aim of this study was to compare current inten... more Tinnitus is the perception of a phantom sound. The aim of this study was to compare current intensity (center anode 1 mA and 2 mA), duration (10 minutes and 20 minutes), and location (left temporoparietal area [LTA] and dorsolateral prefrontal cortex [DLPFC]) using 4 × 1 high-definition transcranial direct current stimulation (HD-tDCS) for tinnitus reduction. Twenty-seven participants with chronic tinnitus (>2 years) and mean age of 53.5 years underwent 2 sessions of HD-tDCS of the LTA and DLPFC in a randomized order with a 1 week gap between site of stimulation. During each session, a combination of 4 different settings were used in increasing dose (1 mA, 10 minutes; 1 mA, 20 minutes; 2 mA, 10 minutes; and 2 mA, 20 minutes). The impact of different settings on tinnitus loudness and annoyance was documented. Twenty-one participants (77.78%) reported a minimum of 1 point reduction on tinnitus loudness or annoyance scales. There were significant changes in loudness and annoyance fo...
Journal of Neuroscience Methods, 2015
Textbook of Tinnitus, 2011
Journal of the American Academy of Audiology, 2014
Background: The authors reviewed practicable options of sound therapy for tinnitus, the evidence ... more Background: The authors reviewed practicable options of sound therapy for tinnitus, the evidence base for each option, and the implications of each option for the patient and for clinical practice.
Journal of the American Academy of Audiology, 2013
Background: Tinnitus can have a devastating impact on the quality of life of the sufferer. Althou... more Background: Tinnitus can have a devastating impact on the quality of life of the sufferer. Although the mechanisms underpinning tinnitus remain uncertain, hearing loss is often associated with its onset, and hearing aids are among the most commonly used tools for its management.
Neurorehabilitation and neural repair
Background – Tinnitus is the phantom perception of sound and can have negative effect on the qual... more Background – Tinnitus is the phantom perception of sound and can have negative effect on the quality of life. Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique, which can increase or decrease the cortical excitability in the brain region to which it is applied. TDCS has been used for tinnitus research since 2006. Objective - To investigate whether tDCS affects tinnitus perception, related emotion, or both, and the potential implications for tinnitus management. Methods - A scoping review was undertaken using the methods proposed by Arksey & O'Malley (2005)1. After initial consideration of title relevance and reading abstracts, 15 studies were included in this review. The data from these studies were charted to investigate the impact of tDCS on tinnitus perception and emotions. Results - TDCS results in transient suppression of tinnitus loudness and annoyance, however it does not lead to long term impact on tinnitus related emotion. Local ...
Neurorehabilitation and Neural Repair, 2013
Neurorehabilitation and Neural Repair, 2013
Journal of Psychosomatic Research, 2012
Tinnitus affects 10% of the population, its pathophysiology remains incompletely understood, and ... more Tinnitus affects 10% of the population, its pathophysiology remains incompletely understood, and treatment is elusive. Functional imaging has demonstrated a relationship between the intensity of tinnitus and the degree of reorganization in the auditory cortex. Experimental studies have further shown that tinnitus is associated with synchronized hyperactivity in the auditory cortex. Therefore, targeted modulation of auditory cortex has been proposed as a new therapeutic approach for chronic tinnitus.
International Journal of Audiology, 2013
Objective: Tinnitus is a perceived sound that cannot be attributed to an external source. This st... more Objective: Tinnitus is a perceived sound that cannot be attributed to an external source. This study attempts to identify a prescription of amplifi cation that is optimized as a fi rst-fi t setting for tinnitus relief. Design : Participants compared the effect of high frequency amplifi cation on their tinnitus. Stimuli were 13 speech fi les with different amounts of high frequency amplifi cation (three cutoff frequencies and four gain settings) to simulate the effects of a change in DSL(I/O) v5.0 prescription in the high frequencies. Study sample: Twenty-fi ve participants with chronic tinnitus participated in the study. Results: A 6-dB reduction to prescribed gain at 2 kHz emerged as the most preferred output (26.47% participants) to interfere with participants ' tinnitus. Overall, 70.58% of the participants ' preferred a 3 to 6 dB reduction in output while 29.42% preferred a similar increase across all cutoff frequencies. A trend was observed in which the higher the tinnitus pitch the more similar the preferred output to DSL(I/O) v5.0. Conclusion: DSL(I/O) v5.0 appears to be a good starting point for prescription of hearing-aid output for tinnitus management. Long-term benefi ts of different prescriptions for tinnitus still need to be ascertained.
Frontiers in Systems Neuroscience, 2012
Models of tinnitus suggest roles for auditory, attention, and emotional networks in tinnitus perc... more Models of tinnitus suggest roles for auditory, attention, and emotional networks in tinnitus perception. A model of tinnitus audibility based on Helson's (1964) adaptation level theory (ALT) is hypothesized to explain the relationship between tinnitus audibility, personality, memory, and attention. This theory attempts to describe how tinnitus audibility or detectability might change with experience and context. The basis of ALT and potential role of auditory scene analysis in tinnitus perception are discussed. The proposed psychoacoustic model lends itself to incorporation into existing neurophysiological models of tinnitus perception. It is hoped that the ALT hypothesis will allow for greater empirical investigation of factors influencing tinnitus perception, such as attention and tinnitus sound therapies.
European Archives of Oto-Rhino-Laryngology, 2014
Tinnitus is the phantom perception of sounds. No single theory explaining the cause of tinnitus e... more Tinnitus is the phantom perception of sounds. No single theory explaining the cause of tinnitus enjoys universal acceptance, however, it is usually associated with hearing loss. The aim of this study was to investigate the relationship between tinnitus pitch and audiometry, minimum masking levels (MML), tinnitus loudness, and distortion product otoacoustic emissions (DPOAE). This was a retrospective analysis of participant's records from the University of Auckland Hearing and Tinnitus Clinic database. The sample consisted of 192 participants with chronic tinnitus (more than 18 months) who had comprehensive tinnitus assessment from March 2008 to January 2011. There were 116 males (mean = 56.5 years, SD = 12.96) and 76 females (mean = 58.7 years, SD = 13.88). Seventy-six percent of participants had a tinnitus pitch C8 kHz. Tinnitus pitch was most often matched to frequencies at which hearing threshold was 40-60 (T50) dBHL. There was a weak but statistically significant positive correlation between tinnitus pitch and T50 (r = 0.15 at p \ 0.05). No correlation was found between tinnitus pitch and DPOAEs, MML, audiometric edge and worst threshold. The strongest audiometric predictor for tinnitus pitch was the frequency at which threshold was approximately 50 dBHL. We postulate that this may be due to a change from primarily outer hair cell damage to lesions including inner hair cells at these levels of hearing loss.
Ear and Hearing, 2012
Chronic subjective tinnitus is a prevalent condition that causes significant distress to millions... more Chronic subjective tinnitus is a prevalent condition that causes significant distress to millions of Americans. Effective tinnitus treatments are urgently needed, but evaluating them is hampered by the lack of standardized measures that are validated for both intake assessment and evaluation of treatment outcomes. This work was designed to develop a new self-report questionnaire, the Tinnitus Functional Index (TFI), that would have documented validity both for scaling the severity and negative impact of tinnitus for use in intake assessment and for measuring treatment-related changes in tinnitus (responsiveness) and that would provide comprehensive coverage of multiple tinnitus severity domains.
Tinnitus is the conscious perception of sound with no physical sound source. Some models of tinni... more Tinnitus is the conscious perception of sound with no physical sound source. Some models of tinnitus pathophysiology suggest that networks associated with attention, memory, distress and multisensory experience are involved in tinnitus perception. The aim of this study was to evaluate whether a multisensory attention training paradigm which used audio, visual, and somatosensory stimulation would reduce tinnitus. Eighteen participants with predominantly unilateral chronic tinnitus were randomized between two groups receiving 20 daily sessions of either integration (attempting to reduce salience to tinnitus by binding with multisensory stimuli) or attention diversion (multisensory stimuli opposite side to tinnitus) training. The training resulted in small but statistically significant reductions in Tinnitus Functional Index and Tinnitus Severity Numeric Scale scores and improved attentional abilities. No statistically significant improvements in tinnitus were found between the training groups. This study demonstrated that a short period of multisensory attention training reduced unilateral tinnitus, but directing attention toward or away from the tinnitus side did not differentiate this effect.
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Papers by Grant Searchfield