Measuring tinnitus in pharmaceutical clinical trials.

This paper reviews methods and considerations for measuring tinnitus in clinical trials designed to evaluate treatment options using investigational medicinal products. Tests applied in tinnitus-related research and clinical practice have their own measurement purposes, advantages, and limitations. If the characteristics of each test method are well understood, the test can be effectively used in clinical trials. For the accuracy of clinical trial results, it is necessary to use a test tool with verified validity, reliability, and sensitivity. If a test tool that is likely to have high variability in the same individual is required in the clinical trial, strategies to increase the reliability of the test, such as repeat measurements, may also be needed. In addition, a test tool that meets the purpose of the clinical trial should be selected. For example, the tinnitus questionnaire is appropriate to assess reactions to tinnitus, and measurements of tinnitus loudness or pitch are appropriate to evaluate the psychoacoustic characteristics of tinnitus. In conclusion, the use of validated test tools that meet the purpose of the trial will help with the accuracy of the clinical trial results.

An Exploratory Study of Bimodal Electro-Aural Stimulation Through the Ear Canals for Tinnitus.

OBJECTIVE: The aim of this study was to explore the potential for bimodal auditory and noninvasive electrical stimulation at the ears to alleviate tonal, somatic tinnitus that was investigated in a small preliminary trial (11 participants). DESIGN: Auditory stimulation took the form of short "notched noise" bursts customized to each participant's tinnitus percept. Simultaneous pulsed electrical stimulation, intended to facilitate neuroplasticity, was delivered via hydrogel electrodes placed in opposite ears. RESULTS: After a 6-week intervention period, average Tinnitus Functional Index (TFI) and Tinnitus Primary Function Questionnaire (TPFQ) scores were consistent with clinically meaningful improvements in the study population. Magnitudes and effect sizes of improvements in TFI and TPFQ are comparable to those reported in other recent bimodal therapy studies using different auditory and electrical stimulation parameters. CONCLUSIONS: Our results should be considered preliminary given the small sample size, lack of crossover data, and small subject pool. When considered alongside other recent bimodal therapy results, we do believe that there are therapeutic benefits of bimodal stimulation for tinnitus sufferers that have the potential to help some with tinnitus, with a variety of stimulation parameters and electrode placements. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25444546.

The contribution of a frequency-compression hearing aid to contralateral cochlear implant performance.

BACKGROUND: Frequency-lowering signal processing in hearing aids has re-emerged as an option to improve audibility of the high frequencies by expanding the input bandwidth. Few studies have investigated the usefulness of the scheme as an option for bimodal users (i.e., combined use of a cochlear implant and a contralateral hearing aid). In this study, that question was posed. PURPOSE: The purposes of this study were (1) to determine if frequency compression was a better bimodal option than conventional amplification and (2) to determine the impact of a frequency-compression hearing aid on speech recognition abilities. RESEARCH DESIGN: There were two separate experiments in this study. The first experiment investigated the contribution of a frequency-compression hearing aid to contralateral cochlear implant (CI) performance for localization and speech perception in noise. The second experiment assessed monaural consonant and vowel perception in quiet using the frequency-compression and conventional hearing aid without the use of a contralateral CI or hearing aid. STUDY SAMPLE: Ten subjects fitted with a cochlear implant and hearing aid participated in the first experiment. Seventeen adult subjects with a cochlear implant and hearing aid or two hearing aids participated in the second experiment. To be included, subjects had to have a history of postlingual deafness, a moderate or moderate-to-severe hearing loss, and have not worn this type of frequency-lowering hearing aid previously. DATA COLLECTION AND ANALYSIS: In the first experiment, performance using the frequency-compression and conventional hearing aids was assessed on tests of sound localization, speech perception in a background of noise, and two self-report questionnaires. In the second experiment, consonant and vowel perception in quiet was assessed monaurally for the two conditions. In both experiments, subjects alternated daily between a frequency-compression and conventional hearing aid for 2 mo. The parameters of frequency compression were set individually for each subject, and audibility was measured for the frequency compression and conventional hearing aid programs by comparing estimations of the Speech Intelligibility Index (SII) using a modified algorithm (Bentler et al, 2011). In both experiments, the outcome measures were administered following the hearing aid fitting to assess performance at baseline and after 2 mo of use. RESULTS: For this group of subjects, the results revealed no significant difference between the frequency-compression and conventional hearing aid on tests of localization and consonant recognition. Spondee-in-noise and vowel perception scores were significantly higher with the conventional hearing aid compared to the frequency-compression hearing aid after 2 mo of use. CONCLUSIONS: These results suggest that, for the subjects in this study, frequency compression is not a better bimodal option than conventional amplification. In addition, speech perception may be negatively influenced by frequency compression because formant frequencies are too severely compressed and can no longer be distinguished.

Willingness to accept and pay for implantable tinnitus treatments: a survey.

OBJECTIVES: At present, there is no cure for tinnitus. Neurostimulation techniques have shown great promise, but it is uncertain whether they will gain acceptance because of their invasive nature. We have previously demonstrated that pairing acoustic stimuli with vagus nerve stimulation (VNS) also has potential as a viable tinnitus treatment approach. METHODS: We conducted a survey on tinnitus sufferers that emphasized questions related to a willingness to pay for the treatment of tinnitus, including VNS. Four hundred thirty-nine individuals responded to an Internet survey modeled after a recent study by Tyler. RESULTS: The average age was about 47 years. Ninety-four percent reported that they had health insurance. Almost 40% had spent between $500 and $10,000 on tinnitus therapies. Almost three-fourths said that they would be willing to have a device implanted if it reduced tinnitus annoyance by half. About 70% of those with very loud tinnitus would be willing to have a temporary implant, and about 60% would be willing to have a permanent implant even if the device suppressed their tinnitus by only half of its annoyance. Only 10% of patients with SOFT tinnitus would be willing to have a permanent implant if the therapy suppressed their tinnitus by only half of its annoyance. CONCLUSIONS: We conclude that implanted devices, such as a VNS, will be an acceptable form of tinnitus treatment for many who suffer from tinnitus. The results of this survey indicate that VNS tone pairing would be an acceptable therapeutic solution for individuals with moderate to severe tinnitus and should be developed for the market.

Tinnitus retraining therapy: mixing point and total masking are equally effective.

OBJECTIVES: Habituation to tinnitus cannot occur with total masking, an argument made by proponents of "tinnitus retraining therapy." We also compared the effectiveness of retraining therapy with mixing-point masking, total masking, and with counseling alone. DESIGN: Forty-eight tinnitus patients were randomly assigned to one of three groups: counseling, counseling plus bilateral noise generators set to completely mask the tinnitus, or counseling plus bilateral noise generators with a focus on the mixing point (partial masking just below total masking). A picture-based counseling protocol was used to assist in providing similar counseling among all three groups. The Tinnitus Handicap Questionnaire was administered before and after about 12 months of treatment. RESULTS: After 12 months, in the counseling group, three of 18 patients benefited significantly, in the mixing-point group, six of 19 patients benefited, and in the total masking group, four of 11 patients benefited from the treatment. The average decrease in the questionnaire was 16.7% for the counseling group, 31.6% for the retraining group, and 36.4% for the total masking group. No significant average differences among groups were observed. CONCLUSIONS: One premise of retraining therapy is incorrect; a focus on mixing-point masking is not required for habituation.

Patient preferences and willingness to pay for tinnitus treatments.

PURPOSE: There will likely be several different tinnitus treatments necessary, and it is important to understand patient preferences and factors that might contribute to treatment acceptability. This study explores the acceptability of a wide range of different tinnitus treatments, from noninvasive wearable devices to surgically implanted devices in the brain. Understanding how tinnitus sufferers consider and rank such options and how they might be influenced by their own perception of the severity of their tinnitus could help clinicians, researchers, and companies plan future efforts for approaching new treatments. DATA COLLECTION AND ANALYSIS: 197 tinnitus self-help group attendees rated their acceptance of treatments on a scale from 0 (not acceptable) to 100 (fully acceptable). The treatments included external devices, medications, cochlear implants, an implant on the brain surface, and an implant in the brain. They were also asked how much they would pay for successful treatments. RESULTS: There was a significant correlation between loudness and annoyance (r = .78). To reduce tinnitus by half, an "acceptable" response between 91 and 100 was reported by 30% of the respondents for devices, by 52% for pills, by 25% for cochlear implants, by 13% for implants on the brain surface, and by 13% for implants in the brain. To reduce tinnitus completely, a 91-100 acceptable response was reported by 42% for devices, by 62% for pills, by 38% for cochlear implants, by 21% for implants on the brain surface, and by 19% for implants in the brain. To reduce tinnitus completely, participants most commonly selected to pay at least $5000, and 20.3% were willing to pay as much as $25,000. The ratings of tinnitus loudness and annoyance were positively correlated with the likelihood of using any treatment. Surprisingly, there was a weak relationship between annoyance and the amount they were willing to pay. CONCLUSIONS: Tinnitus patients are prepared to accept a wide variety of treatments. Medications are the most acceptable. Invasive procedures can also be acceptable to many, particularly if they provide complete relief.

Validation of the Chinese Translation of the "Meaning of Life" in Patients with Hearing Loss or Tinnitus.

BACKGROUND: There is an increasing need to evaluate the quality of life of hearing-impaired individuals. However, most of the generic "quality of life" questionnaires do not include communication-related questions. Recently, a new "Meaning of Life" questionnaire was developed to measure quality of life based on everyday issues, enabling a comprehensive evaluation of tinnitus patients and cochlear implant users. A Chinese version of this questionnaire for the Mandarin population is needed. PURPOSE: We aimed to translate and validate the Meaning of Life (MOL) questionnaire into Chinese to make it applicable as a tool for measuring quality of life in patients with hearing loss or tinnitus. RESEARCH DESIGN: For this study, the original version of the MOL questionnaire was translated into the Chinese language. A prospective cohort study was then performed on adults with hearing loss or tinnitus to preliminarily examine the reliability and validity of the Chinese version. STUDY SAMPLE: A total of 206 Mandarin-speaking subjects with hearing loss or tinnitus were included in the study and divided into three groups according to their chief complaints: Group B included patients suffering from both hearing loss and tinnitus (N = 113), group T contained patients with tinnitus alone (N = 49), and group H was composed of patients with hearing loss alone (N = 44). DATA COLLECTION AND ANALYSIS: The Chinese version of the MOL (C-MOL) was administered to the participants. The reliability of the C-MOL was evaluated using Cronbach's α and item-total correlation (ITC) coefficients. Exploratory factor analysis was performed to examine the relationships among the questions. Correlations between the patient characteristics and total scores were tested. RESULTS: The Cronbach's α-coefficient of C-MOL was 0.921. Four factors were identified by exploratory factor analysis: (1) mental state and positive outlook; (2) friendship; (3) physical health; and (4) hearing and negative experience. The total scores of groups B, T, and H were 76.4 (SD = 13.5), 81.3 (SD = 10.6), and 82.4 (SD = 12.5), respectively. The total score was correlated with the affected ears (r = 0.179, p < 0.05), age (r = 0.179, p < 0.05), hearing of the better ear (r = 0.188, p < 0.01), and educational background (r = 0.181, p < 0.01). CONCLUSIONS: The Chinese version of the MOL questionnaire showed good reliability. It can be used to quantify the quality of life of patients with hearing loss or tinnitus.

Reliability and Validity of the Tinnitus Handicap Inventory: A Clinical Study of Questionnaires.

BACKGROUND: The aim of this study is to observe the application of the Chinese version of Tinnitus Handicap Inventory-China in Tinnitus patients and verify its reliability and validity. METHODS: About 1129 patients with tinnitus as the first complaint were selected as subjects. The patients were randomly divided into 2 groups: exploration group (n = 565), whose data were analyzed with reliability analysis method using Statistical Package for the Social Sciences software 19.0, validation group (n = 564), whose data were analyzed with validity analysis method using AMOS21.0. RESULTS: (1) Reliability test: The Cronbach's α coefficients of the Tinnitus Handicap Inventory-China scale in both groups were 0.94, among which, the Cronbach's α coefficients of functional factor (F), emotion factor (E), and catastrophic factor (C) in group E were 0.87, 0.90, and 0.78, respectively. The half-reliability of the 2 components is 0.87. The correlation coefficient between items and the scale in group E and group V is 0.36-0.78 and 0.33-0.77, respectively. (2) Content validity: The Kaiser-Meyer-Olkin value of group E is 0.96, a total of 4 common factors were extracted, and the cumulative interpretation rate is 57.844%. The number of factors with load less than 0.4 on the 4 common factors is only 1 (F24), suggesting that this factor had little significance; the number of factors with load more than 0.4 on the 2 common factors is 8 (F1, E6, F9, C11, F15, E21, E22, and C23), suggesting that patients had different understandings of these 8 questions. (3) Structural validity: The root mean square error of approximation value of the AMOS structural model in group V is 0.065, and the root mean square residual value is 0.114, indicating low fitness; the NC value is 3.353, indicating good fitness of the scale, but it still needed to be simplified. CONCLUSION: The Chinese version of Tinnitus Handicap Inventory-China has a high reliability when applied in China, but the content validity and structure validity are not high, and the clinical practicability needs to be improved.

Hypothyroidism and related comorbidities on the risks of developing tinnitus.

This is a retrospective longitudinal study that uses data from the National Health Insurance Research Database (NHIRD) of Taiwan of which hypothyroid patients who received a diagnosis between 2000 and 2010 were selected and followed up until 2011. The primary outcome of this study was the occurrence of tinnitus (ICD-9-CM code 388.3). The relevant comorbidities were selected as potential confounders according to the literature, which included vertigo (ICD-9-CM code 386), insomnia (ICD-9-CM code 780), anxiety (ICD-9-CM code 300.00), and hearing loss (ICD-9-CM code 388-389). The overall incidence of tinnitus was significantly higher in the hypothyroidism cohort than in the non-hypothyroidism cohort (9.49 vs. 6.03 per 1000 person-years), with an adjusted HR of 1.35 (95% CI 1.18-1.54) after adjusting potential confounders. The incidences of tinnitus, as stratified by gender, age, comorbidity, and follow-up time, were all significantly higher in the hypothyroidism cohort than those in the non-hypothyroidism cohort. The incidence of tinnitus significantly increased with age (aHR = 1.01, 95% CI 1.01-1.02). In conclusion, we report the relationship between hypothyroidism and the increased risk for tinnitus. We also found that hypothyroidism patients are at increased risk of developing tinnitus when associated with comorbidities including vertigo, hearing loss, and insomnia.

Tinnitus Activities Treatment with Total and Partial Masking.

BACKGROUND: There are many counseling and sound therapy approaches to treat tinnitus. Counseling approaches range from providing information using directive or collaborative approaches. Sound therapies include strategies that use background sounds to totally or partially mask tinnitus to reduce the prominence of or decrease the loudness or annoyance of the tinnitus. PURPOSE: We evaluated the effectiveness of tinnitus activities treatment (TAT) in two groups, those without hearing aids (HA) and those who were provided with HA. In both groups, comparisons were made among those receiving (1) counseling only, (2) counseling and partial masking, and (3) counseling and total masking. RESEARCH DESIGN: Participants were provided with HA or not, based on their choice, and then randomly assigned to one of the three groups. The Tinnitus Handicap Questionnaire (THQ) was used as the primary measure. RESULTS: For those without HA, significant benefits were obtained for 8 out of 22 participants in the counseling group, 8 of 13 in the total masking group, and 8 of 24 in the partial mask group. The average decrease in the THQ was 15% for the counseling group, 25% for the total mask, and 14% for the partial masking group. For those with HA; significant benefits were obtained for 5 of 16 in the counseling group, 3 of 14 in the total mask group, and 6 of 13 in the partial mask group. The average decrease in the THQ score was 12% for counseling, 13% for total masking, and 16% for partial masking. No significant differences among groups were observed. CONCLUSION: Individual differences were large. Many benefited from their treatment, but some did not. We believe this was likely influenced by their expectations.

Use of a Smartphone App for Cochlear Implant Patients With Tinnitus.

Purpose Smartphone apps for tinnitus relief are now emerging; however, research supporting their use and effectiveness is lacking. Research has shown that Tinnitus Therapy sounds intended for individuals with acoustic hearing provide relief to some patients using cochlear implants (CIs) with tinnitus. Here, we evaluated the use and acceptability of a smartphone app to help CI patients with tinnitus. Method Participants completed a laboratory trial (n = 19) and an at-home trial (n = 14) using the ReSound Tinnitus Relief app to evaluate its acceptability and effectiveness in reducing their tinnitus. During the laboratory trial, participants selected a sound that was most acceptable in managing their tinnitus (termed chosen sound). Word recognition scores in quiet were obtained before and after sound therapy. Participants were randomly assigned to one of two groups for the at-home trial, that is, AB or BA, using (A) the chosen sound for 2 weeks and (B) the study sound (i.e., broadband noise at hearing threshold) for another 2 weeks. Ratings were collected weekly to determine acceptability and effectiveness of the app in reducing tinnitus loudness and annoyance. Results Results indicated that some, but not all, participants found their chosen sound to be acceptable and/or effective in reducing their tinnitus. A majority of the participants rated the chosen sound or the study sound to be acceptable in reducing their tinnitus. Word recognition scores for most participants were not adversely affected using the chosen sound; however, a significant decrease was observed for three participants. All 14 participants had a positive experience with the app during the at-home trial on tests of sound therapy acceptability, effectiveness, and word recognition. Conclusions Sound therapy using a smartphone app can be effective for many tinnitus patients using CIs. Audiologists should recommend a sound and a level for tinnitus masking that do not interfere with speech perception.

Association between exposure to road traffic noise and hearing impairment: a case-control study.

PURPOSE: Noise pollution in urban areas is increasing steadily, and the study of road traffic noises and their effects on the auditory system was rare. This study investigated the potential effects of road traffic noise on auditory systems and hearing. METHODS: A case-control study recruited outpatients from the Otolaryngology department. The case group (n = 41) had binaural hearing loss (HL) of standard pure-tone average(PTA) ≥ 25 dB or high frequency PTA ≥ 25 dB, while the control group (n = 39) had binaural hearing level of any frequency < 25 dB. Detailed otologic evaluations were performed. Between-group data were evaluated using logistic regression analysis. Case or control group was identified based on the audiogram. RESULTS: A total of 80 subjects were recruited, including 41 with hearing impairment and 39 as control. The mean exposure level of road traffic noise was significantly higher in the case group than the control group (p = 0.005). A crude OR of 5.78 showed an increased risk of greater than 70 dB of road traffic noise on hearing impairment and tinnitus (p < 0.001). The aOR of 9.24 (p = 0.002) from a multiple variate analysis suggested that road traffic noise levels greater than 70 dB may have a damaging effect on hearing. Damaging effects on hearing persisted even after adjusting for confounders in the full multivariate model (aOR of 9.24 [95% CI: 2.198-38.869]; p = 0.002). CONCLUSIONS: Exposing to road traffic noise greater than 70 dB showed an increased risk of damage to the auditory system. These results might help public health administrators and physicians to develop programs that address the health dangers of noise.

Increased Incidence of Tinnitus Following a Hyperthyroidism Diagnosis: A Population-Based Longitudinal Study.

Background: An association between thyroid disease and tinnitus has been described previously but further longitudinal, population-based studies are limited. Objective: To investigate the incidence of tinnitus in patients with hyperthyroidism in a national sample, and to identify risk level and associated factors for tinnitus in hyperthyroidism patients. Design: Retrospective cohort study. Patient data were collected from the Longitudinal Health Insurance Database (LHID 2000), which includes national claims data of patient expenditures for admissions or ambulatory care from 1996 to 2011. Setting: Taiwan hospitals and clinics providing healthcare nationwide. Participants: Patients aged 20 years and older with newly diagnosed hyperthyroidism (ICD-9-CM code 242) between 2000-2010 were selected as the study cohort. Hyperthyroidism patient cohort were identified from the LHID2000. Those with tinnitus history (ICD-9-CM code 388.3) before the index date (first hyperthyroidism diagnosis), younger than 20 years, and with incomplete demographic data were excluded. The non-hyperthyroidism cohort included patients with no history of hyperthyroidism and no documented tinnitus. Main Outcomes and Measures: Incidence of tinnitus was the primary outcome. Baseline demographic factors and comorbidities possibly associated with tinnitus, including age, sex, and comorbidities of hearing loss, vertigo, insomnia and anxiety, were retrieved from the LHID 2000. Patients were followed until end of 2011. Results: During the study period, 780 (4.9%) hyperthyroidism patients and 2007 (3.2%) non-hyperthyroidism controls developed tinnitus. Incidence rate of tinnitus in the hyperthyroidism cohort was significantly higher in hyperthyroidism cohort (7.86 vs. 5.05 per 1000 person-years) than that in non-hyperthyroidism cohort. A higher proportion of patients with hyperthyroidism had comorbid insomnia (45.1% vs. 30.9%) and anxiety (14.0% vs. 5.73%) than those without hyperthyroidism. After adjusting for age, gender and comorbidities (vertigo, insomnia, anxiety, hearing loss), hyperthyroidism patients had 1.38-fold higher risk of tinnitus (95% CI = 1.27-1.50) than those without hyperthyroidism. Conclusions: This large population-based study suggests patients with diagnosed hyperthyroidism was more prone to develop tinnitus. Our findings suggest evaluation for comorbid vertigo, insomnia, anxiety and/or hearing loss may identify patients who are at high risk of developing tinnitus in patients with hyperthyroidism.

Bilateral and unilateral cochlear implant users compared on speech perception in noise.

OBJECTIVE: Compare speech performance in noise with matched bilateral cochlear implant (CICI) and unilateral cochlear implant (CI only) users. DESIGN: Thirty CICI and 30 CI-only subjects were tested on a battery of speech perception tests in noise that use an eight-loudspeaker array. RESULTS: On average, CICI subject's performance with speech in noise was significantly better than the CI-only subjects. CONCLUSION: The CICI group showed significantly better performance on speech perception in noise compared with the CI-only subjects, supporting the hypothesis that CICI is more beneficial than CI only.

The effect of reducing the number of electrodes on spatial hearing tasks for bilateral cochlear implant recipients.

BACKGROUND: Many studies have documented the effect of reducing spectral information for speech perception in listeners with normal hearing and hearing impairment. While it is understood that more spectral bands are needed for unilateral cochlear implant listeners to perform well on more challenging listening tasks such as speech perception in noise, it is unclear how reducing the number of spectral bands or electrodes in cochlear implants influences the ability to localize sound or understand speech with spatially separate noise sources. PURPOSE: The purpose of this study was to measure the effect of reducing the number of electrodes for patients with bilateral cochlear implants on spatial hearing tasks. RESEARCH DESIGN: Performance on spatial hearing tasks was examined as the number of bilateral electrodes in the speech processor was deactivated equally across ears and the full frequency spectrum was reallocated to a reduced number of active electrodes. Program parameters (i.e., pulse width, stimulation rate) were held constant among the programs and set identically between the right and left cochlear implants so that only the number of electrodes varied. STUDY SAMPLE: Nine subjects had used bilateral Nucleus or Advanced Bionics cochlear implants for at least 12 mo prior to beginning the study. Only those subjects with full insertion of the electrode arrays with all electrodes active in both ears were eligible to participate. DATA COLLECTION AND ANALYSIS: Two test measures were utilized to evaluate the effect of reducing the number of electrodes, including a speech-perception-in-noise test with spatially separated sources and a sound source localization test. RESULTS: Reducing the number of electrodes had different effects across individuals. Three patterns emerged: (1) no effect on localization (two of nine subjects), (2) at least two to four bilateral electrodes were required for maximal performance (five of nine subjects), and (3) performance gradually decreased across conditions as electrode number was reduced (two of nine subjects). For the test of speech perception in spatially separated noise, performance was affected as the number of electrodes was reduced for all subjects. Two categories of performance were found: (1) at least three or four bilateral electrodes were needed for maximum performance (five of seven subjects) and (2) as the number of electrodes were reduced, performance gradually decreased across conditions (two of seven subjects). CONCLUSION: Large individual differences exist in determining maximum performance using bilateral electrodes for localization and speech perception in noise. For some bilateral cochlear implant users, as few as three to four electrodes can be used to obtain maximal performance on localization and speech-in-noise tests. However, other listeners show a gradual decrement in performance on both tasks when the number of electrodes is reduced.

Benefits of localization and speech perception with multiple noise sources in listeners with a short-electrode cochlear implant.

BACKGROUND: Research suggests that for individuals with significant low-frequency hearing, implantation of a short-electrode cochlear implant may provide benefits of improved speech perception abilities. Because this strategy combines acoustic and electrical hearing within the same ear while at the same time preserving low-frequency residual acoustic hearing in both ears, localization abilities may also be improved. However, very little research has focused on the localization and spatial hearing abilities of users with a short-electrode cochlear implant. PURPOSE: The purpose of this study was to evaluate localization abilities for listeners with a short-electrode cochlear implant who continue to wear hearing aids in both ears. A secondary purpose was to document speech perception abilities using a speech-in-noise test with spatially separate noise sources. RESEARCH DESIGN: Eleven subjects that utilized a short-electrode cochlear implant and bilateral hearing aids were tested on localization and speech perception with multiple noise locations using an eight-loudspeaker array. Performance was assessed across four listening conditions using various combinations of cochlear implant and/or hearing aid use. RESULTS: Results for localization showed no significant difference between using bilateral hearing aids and bilateral hearing aids plus the cochlear implant. However, there was a significant difference between the bilateral hearing aid condition and the implant plus use of a contralateral hearing aid for all 11 subjects. Results for speech perception showed a significant benefit when using bilateral hearing aids plus the cochlear implant over use of the implant plus only one hearing aid. CONCLUSION: Combined use of both hearing aids and the cochlear implant show significant benefits for both localization and speech perception in noise for users with a short-electrode cochlear implant. These results emphasize the importance of low-frequency information in two ears for the purpose of localization and speech perception in noise.

Initial development of a spatially separated speech-in-noise and localization training program.

OBJECTIVE: This article describes the initial development of a novel approach for training hearing-impaired listeners to improve their ability to understand speech in the presence of background noise and to also improve their ability to localize sounds. DESIGN: Most people with hearing loss, even those well fit with hearing devices, still experience significant problems understanding speech in noise. Prior research suggests that at least some subjects can experience improved speech understanding with training. However, all training systems that we are aware of have one basic, critical limitation. They do not provide spatial separation of the speech and noise, therefore ignoring the potential benefits of training binaural hearing. In this paper we describe our initial experience with a home-based training system that includes spatially separated speech-in-noise and localization training. RESULTS: Throughout the development of this system patient input, training and preliminary pilot data from individuals with bilateral cochlear implants were utilized. Positive feedback from subjective reports indicated that some individuals were engaged in the treatment, and formal testing showed benefit. Feedback and practical issues resulted from the reduction of an eight-loudspeaker to a two-loudspeaker system. CONCLUSIONS: These preliminary findings suggest we have successfully developed a viable spatial hearing training system that can improve binaural hearing in noise and localization. Applications include, but are not limited to, hearing with hearing aids and cochlear implants.

Performance over time on adults with simultaneous bilateral cochlear implants.

BACKGROUND: Maximum performance and long-term stability of bilateral cochlear implants has become an important topic because there has been increasing numbers of recipients of bilateral cochlear implants. PURPOSE: To determine the performance over time (up to 6yr) of subjects with simultaneous bilateral cochlear implants (CI+CI) on word recognition and localization. RESEARCH DESIGN: Over-time investigation of word recognition in quiet (CNC) and sound localization in quiet (Everyday Sounds Localization Test). STUDY SAMPLE: The subjects were 48 adults who simultaneously received their cochlear implants at the University of Iowa. RESULTS: For word recognition, percent correct scores continuously improved up to 1 yr postimplantation with the most benefit occurring within the first month of implantation. In observing up to 72 mo, the averaged scores reached to the plateau of about 63% correct in CNC after 2 yr (N = 31). But, when we followed 17 subjects who have complete data set between 12 mo and 48+ months, word recognition scores were significantly different from 12 mo to 48 + months, which implies binaural advantages need more time to be developed. Localization test results suggested that the root mean square (RMS) error scores continuously improved up to 1 yr postimplantation with most benefits occurring within the first 3 mo. After 2 yr, the averaged scores reached to the plateau of about 20 degrees RMS error (N = 27). When we followed 10 subjects who have complete data set between 12 mo and 48+ months, localization scores were not improved from 12 mo to 48+ months. There were large individual differences in performance over time. CONCLUSIONS: In general, substantial benefits in both word recognition and localization were found over the first 1-12 mo postimplantation for subjects who received simultaneous bilateral cochlear implants. These benefits were maintained over time up to 6yr postimplantation.

An attempt to improve bilateral cochlear implants by increasing the distance between electrodes and providing complementary information to the two ears.

OBJECTIVES: The purpose of this investigation was to determine if adult bilateral cochlear implant recipients could benefit from using a speech processing strategy in which the input spectrum was interleaved among electrodes across the two implants. DESIGN: Two separate experiments were conducted. In both experiments, subjects were tested using a control speech processing strategy and a strategy in which the full input spectrum was filtered so that only the output of half of the filters was audible to one implant, while the output of the alternative filters was audible to the other implant. The filters were interleaved in a way that created alternate frequency "holes" between the two cochlear implants. RESULTS: In experiment one, four subjects were tested on consonant recognition. Results indicated that one of the four subjects performed better with the interleaved strategy, one subject received a binaural advantage with the interleaved strategy that they did not receive with the control strategy, and two subjects showed no decrement in performance when using the interleaved strategy. In the second experiment, 11 subjects were tested on word recognition, sentences in noise, and localization (it should be noted that not all subjects participated in all tests). Results showed that for speech perception testing one subject achieved significantly better scores with the interleaved strategy on all tests, and seven subjects showed a significant improvement with the interleaved strategy on at least one test. Only one subject showed a decrement in performance on all speech perception tests with the interleaved strategy. Out of nine subjects, one subject preferred the sound quality of the interleaved strategy. No one performed better on localization with the interleaved strategy. CONCLUSION: Data from this study indicate that some adult bilateral cochlear implant recipients can benefit from using a speech processing strategy in which the input spectrum is interleaved among electrodes across the two implants. It is possible that the subjects in this study who showed a significant improvement with the interleaved strategy did so because of less channel interaction; however, this hypothesis was not directly tested.

Complaints of People with Hyperacusis.

BACKGROUND: Hyperacusis is a prevalent auditory disorder that causes significant distress and negatively affects quality of life for many patients. Patients with hyperacusis often have different complaints about the sounds and situations that they experience. Audiologists may have few patients with hyperacusis, and a limited understanding of the sounds and situations that are reported to be challenging by their patients. PURPOSE: To investigate the common complaints reported by hyperacusis patients. RESEARCH DESIGN: A qualitative study was conducted with 11 hyperacusis patients who participated in a group session. RESULTS: All 11 hyperacusis patients experienced negative reactions to specific sounds. In addition, many patients reported physical symptoms such as headaches, balance problems, dysosmia (strong smell problems), and light sensitivity. Sounds that induced discomfort were wide ranging and included low-frequency sounds, high-frequency sounds, wide-band noise, and sudden, high-intensity sounds. Most patients (9/11, 81.8%) reported negative reactions to music in loud rock concerts. Patients reported that stress/tension (90.9%) worsened their hyperacusis, while removing themselves from noise (90.9%) relieved their hyperacusis. CONCLUSION: Loudness is only one of the many factors related to the discomfort of patients with hyperacusis. Across patients, we observed that there were different complaints about the sounds and situations that produced difficulty due to hyperacusis. Physical symptoms following sound exposure were also reported by the patients, suggesting that hyperacusis is a complex disorder and requires intervention that often involves multiple members of the medical team.