Objective measurement of subjective tinnitus using the acoustic change complex

PLOS ONE, Nov 2019

At present, there is no objective method for diagnosing subjective sensorineural tinnitus. Recently, the acoustic change complex (ACC) has been used to evaluate neural detection of sounds. Thus, the present study aimed to examine whether the ACC can reflect cortical detection and discrimination of sounds matched with tinnitus frequencies. We hypothesized that the ACC to change stimuli matched with tinnitus frequencies would be decreased in tinnitus patients because the tinnitus interferes with the perception of acoustic changes. To test the hypothesis, 96 ears of normal-hearing (NH) tinnitus patients and controls were tested. Among the tinnitus patients, 33 ears with a tinnitus frequency of 8 kHz constituted the tinnitus group, and the remaining 63 ears with no experience of tinnitus were allocated to the control group. For the 4 kHz non-tinnitus matched frequency, a subset of tinnitus (n = 17) and NH (n = 47) subjects was tested. The acoustic stimuli were pure tones with a total duration of 500 ms consisting of a 1 kHz tone in the first 250 ms and a second tone of either 8 kHz or 4 kHz in the latter 250 ms. The normalized amplitude of the ACC (naACC) was calculated separately for the amplitude of the N1’-P2’ complex evoked by an 8 kHz or 4 kHz change stimulus and for the amplitude of the N1-P2 complex elicited by the initial 1 kHz background stimulus. Our results showed that the naACC to an 8 kHz stimulus in the tinnitus group was significantly smaller than those to 4 kHz and 8 kHz in normal controls. Additionally, in the tinnitus group, the naACC to 4 kHz was greater compared to 8 kHz. The receiver operating characteristic (ROC) curve analysis conducted for naACC to 8 kHz at UCL revealed a fair degree of diagnostic efficacy. Overall, our results indicated that the ACC to a change stimulus matched with the tinnitus frequency can provide an objective measure of frequency-specific tinnitus.

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Objective measurement of subjective tinnitus using the acoustic change complex

November Objective measurement of subjective tinnitus using the acoustic change complex Ji-Hye Han 0 1 Joong Yeon Won 1 Sung Kwang Hong 0 1 Ja Hee Kim 0 1 Eun Soo Kim 1 Hyung- Jong Kim 0 1 Hyo-Jeong Lee 0 1 0 Laboratory of Brain & Cognitive Sciences for Convergence Medicine, Hallym University College of Medicine, Chuncheon, Republic of Korea, 2 Department of Otolaryngology, Hallym University College of Medicine, Chuncheon, Republic of Korea, 3 Department of Neuroradiology, Hallym University College of Medicine , Chuncheon , Republic of Korea 1 Editor: Jyrki Ahveninen, Harvard Medical School , UNITED STATES At present, there is no objective method for diagnosing subjective sensorineural tinnitus. Recently, the acoustic change complex (ACC) has been used to evaluate neural detection of sounds. Thus, the present study aimed to examine whether the ACC can reflect cortical detection and discrimination of sounds matched with tinnitus frequencies. We hypothesized that the ACC to change stimuli matched with tinnitus frequencies would be decreased in tinnitus patients because the tinnitus interferes with the perception of acoustic changes. To test the hypothesis, 96 ears of normal-hearing (NH) tinnitus patients and controls were tested. Among the tinnitus patients, 33 ears with a tinnitus frequency of 8 kHz constituted the tinnitus group, and the remaining 63 ears with no experience of tinnitus were allocated to the control group. For the 4 kHz non-tinnitus matched frequency, a subset of tinnitus (n = 17) and NH (n = 47) subjects was tested. The acoustic stimuli were pure tones with a total duration of 500 ms consisting of a 1 kHz tone in the first 250 ms and a second tone of either 8 kHz or 4 kHz in the latter 250 ms. The normalized amplitude of the ACC (naACC) was calculated separately for the amplitude of the N1'-P2' complex evoked by an 8 kHz or 4 kHz change stimulus and for the amplitude of the N1-P2 complex elicited by the initial 1 kHz background stimulus. Our results showed that the naACC to an 8 kHz stimulus in the tinnitus group was significantly smaller than those to 4 kHz and 8 kHz in normal controls. Additionally, in the tinnitus group, the naACC to 4 kHz was greater compared to 8 kHz. The receiver operating characteristic (ROC) curve analysis conducted for naACC to 8 kHz at UCL revealed a fair degree of diagnostic efficacy. Overall, our results indicated that the ACC to a change stimulus matched with the tinnitus frequency can provide an objective measure of frequency-specific tinnitus. - Data Availability Statement: All relevant data are within the paper and its supporting information file (S1 Dataset). Funding: This study was supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Korean Government (NRF-2013R1A1A3006802 and NRF-2016R1A2B4016330, HJL, http://www. nrf.re.kr/nrf_eng_cms/) and the Hallym University Research Fund (HURF-2016-39, HJL and ESK, http://cms.hallym.ac.kr/user/indexMain.do?siteId= english). The funders had no role in study design, Introduction Tinnitus is the subjective perception of sound without an external acoustic stimulation. Tinnitus is a common hearing disorder, with a prevalence ranging from 10% to 20%, and data collection and analysis, decision to publish, or preparation of the manuscript. approximately 40% of people with tinnitus report severe impairments in their quality of life [1±4]. Due to its subjective nature, a verification of tinnitus depends solely on a subjective report from the patient. In animal models of tinnitus, a modification of the acoustic startle reflex (ASR) has been used as an objective measure of tinnitus [5±8]. For example, in normal rats, a silent gap inserted into background noise decreased the ASR in response to a loud startling stimulus, while in the animals with tinnitus, the background noise with a frequency close to the tinnitus frequency did not decrease the ASR [ 5 ]. To explain this lack of inhibition, it was suggested that the tinnitus sound fills the silent gap inserted into the background noise, which is close to the tinnitus frequency. Thus, animals with tinnitus perceived the stimulus as noise with no gap. This objective measure of tinnitus in animals was recently applied to tinnitus patients in an attempt to develop a clinical diagnostic tool [ 9 ]. Although a hypothesis that a tinnitus sound fills in a gap appears highly plausible, previous studies have shown that the decreased magnitude of a startle reflex in tinnitus patients was not specific to the tinnitus frequency, and the studies attributed the disinhibition of ASR to other central auditory circuits involved in gap processing. However, a psychoacoustic study paradoxically reported that tinnitus patients did not show a perceptual deficit in a gap detection task [ 10 ]. Recently, the auditory change complex (ACC) comprised of the cortical N1-P2 responses evoked by stimuli with acoustic changes has been u (...truncated)


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Ji-Hye Han, Joong Yeon Won, Sung Kwang Hong, Ja Hee Kim, Eun Soo Kim, Hyung-Jong Kim, Hyo-Jeong Lee. Objective measurement of subjective tinnitus using the acoustic change complex, PLOS ONE, 2017, Volume 12, Issue 11, DOI: 10.1371/journal.pone.0188268