Tinnitus Masking Research Articles

Clinical Guide for Audiologic Tinnitus Management II

This article is the second of 2 that address the need for basic procedures that can be used commonly by audiologists to manage patients with clinically significant tinnitus, as well as hyperacusis. The method described is termed audiologic tinnitus management (ATM). ATM was developed specifically for use by audiologists. Although certain procedural components were adapted from the methods of tinnitus masking and tinnitus retraining therapy, ATM is uniquely and specifically defined. A detailed description of the ATM assessment procedures is provided in the companion article (J. A. Henry, T. L. Zaugg, & M. A. Schechter, 2005). The present article describes a specific clinical protocol for providing treatment with ATM. The treatment method described for ATM includes structured informational counseling and an individualized program of sound enhancement that can include the use of hearing aids, ear-level noise generators, combination instruments (noise generator and hearing aid combined), personal listening devices (wearable CD, tape, and MP3 players), and augmentative sound devices (e.g., tabletop sound generators). Ongoing treatment appointments involve primarily the structured counseling, evaluation, and adjustment of the use of sound devices, and assessment of treatment outcomes. The informational counseling protocol and an interview form for determining treatment outcomes are each described in step-by-step detail for direct clinical application. This article can serve as a practical clinical guide for audiologists to provide treatment for tinnitus in a uniform manner.

Clinical Guide for Audiologic Tinnitus Management I

This article is the first of 2 that present basic guidelines for audiologists to provide clinical management of tinnitus. The method, termed audiologic tinnitus management (ATM), was developed to incorporate management strategies that can be implemented most efficiently by audiologists. Development of ATM has been drawn from the clinical and research experience of the authors and numerous audiologists. Certain elements of ATM are adapted from the methods of tinnitus masking and tinnitus retraining therapy. Procedures are described in the present article for performing the intake assessment, while the companion article (J. A. Henry, T. L. Zaugg, & M. A. Schechter, 2005) describes treatment methodology. Development of ATM has resulted in defined procedures to conduct a basic tinnitus assessment that includes written questionnaires, an intake interview, audiologic evaluation, and a psychoacoustic assessment of tinnitus perceptual characteristics. If patients report a sound tolerance problem (hyperacusis), loudness discomfort levels are measured at audiometric frequencies. There are special procedures for selecting hearing aids, ear-level noise generators, combination devices (noise generator and hearing aid combined), and personal listening devices (i.e., portable radios and tape, CD, and MP3 players). This article explains each of these assessment components in detail. Adoption of the ATM assessment protocol by audiologists can contribute to the establishment of uniform procedures for the clinical management of tinnitus patients.

顔面神経下顎縁枝刺激による耳鳴の抑制

This study was performed to investigate the idea inhibition of tinnitus by blocking abnormal afferent impulses, which cause tinnitus in the cochlear nerve, from comparatively peripheral regions of the auditory tract. Frequent stimulations were given transcutaneously on the Ramus marginalis mandibular of the facial nerve in 91 cases of tinnitus who experienced noise within ear, and 30 cases who experienced noise in the head or who experienced noise in a region except the ear. Every one of these patients had suffered from an unpleasant feeling every day for more than 6 months. Results were as follows:1. A subjective improvement was observed in 89.0% of patients with tinnitus, and not observed in 93.3% of patients who experienced noise in head.2. Improvement in tests for the patients with tinnitus was demonstrated in 88.7% of cases by tinnitus masking carves, and in 67.8% of cases by loudness balance tests.3. The subjective improvement of tinnitus obtained by frequent stimulations is experienced as not only a reduction of loudness, but sensuous changes such as the thinning or softening of sound, or the scattering of sound.4. 81.1% of patients with tinnitus reported that their tinnitus returned to the previous level within 1 week after frequent stimulations.5. By comparing the right side and the left side in 78.3% of patients with tinnitus in both sides, an improvement of tinnitus was observed after more than one week when frequent stimulation was given one time to 5 times within a week.6. There were no problems caused by stimulation.

Comparison of Custom Sounds for Achieving Tinnitus Relief

Tinnitus masking has been a widely used method for treating clinically significant tinnitus. The method, referred to herein as "sound-based relief," typically uses wearable ear-level devices ("maskers") to effect palliative tinnitus relief. Although often effective, this approach is limited to the use of broadband noise with the maskers. We hypothesized that the effectiveness of treatment can be improved by expanding the auditory-stimulus options available to patients. A pilot study was conducted to determine for each of 21 subjects the most effective of custom sounds that are designed to promote tinnitus relief. While sitting in a sound booth, subjects listened to white noise and to custom sounds that are available commercially for providing tinnitus relief. Three sound formats ("E-Water," "E-Nature," and "E-Air") were provided by the Dynamic Tinnitus Mitigation (DTM-6a) system (Petroff Audio Technologies, Inc.). Additionally, seven sounds were provided by the Moses/Lang CD7 system (Oregon Hearing Research Center). Considering group data, all of the sounds provided a significant reduction in tinnitus annoyance relative to the annoyance of tinnitus alone. Two of the commercial sounds (DTM E-Nature and E-Water) were judged significantly more effective than the other sounds.

Comparison of Tinnitus Masking and Tinnitus Retraining Therapy

Two methods for treating tinnitus are compared. Tinnitus masking has been used for over 25 years, and although this method is used in clinics around the world, there are many misconceptions regarding the proper protocol for its clinical application. Tinnitus retraining therapy has been used clinically for over 12 years and has received considerable international attention. Although these methods are distinctive in their basic approach to tinnitus management, certain aspects of treatment appear similar. These aspects of treatment have created considerableconfusion and controversy, especially regarding the use of "sound therapy" as a basic component of treatment. It is the objective of this article to clarify the major differences that exist between these two forms of treatment.

Assessment and Treatment of Tinnitus Patients Using a "Masking Approach"

Audiology clinics are increasingly being asked to provide tinnitus treatment services to patients who are severely distressed by tinnitus. It is unclear what levels of tinnitus care are available at different audiology clinics across the nation. Some clinics have staff who are experienced with the tinnitus masking technique or with tinnitus retraining therapy (TRT), whereas other clinics may limit their care to the provision of hearing aids. This article is an attempt to provide some basic information for those clinicians who would like to provide at least a minimum level of care for their tinnitus patients using the tinnitus masking approach. The most important requirement is a commitment by the clinician to assemble some basic resources and to structure the clinical schedule so that adequate time is available for historical review, evaluation, trial and selection of devices, and tinnitus counseling. A minimum set of measurements is recommended for inclusion in the tinnitus evaluation process. This informal review summarizes a variety of clinical observations culled from years of direct patient care experience. A tinnitus questionnaire is provided to help clinicians review potentially relevant issues.

Computer-based method for the diagnostics and rehabilitation of tinnitus patients

The proposed method is an electronic diagnostic and rehabilitation system for people suffering from internal ear noise, namely tinnitus patients and people with an abnormally high hearing sensitivity—hyperacusis patients. Thanks to the method employing multimedia personal computers to the fitting masking sounds to the patient’s needs, tinnitus patients can be rehabilitated using the masking or habituation method. The subject is asked to answer detailed questions in the electronic questionnaire and next to identify those sounds which most strongly resemble those they perceive as ear noise. Following an algorithm analysis of the results and analysis of the selection of sounds made by the patient, the computer diagnoses the patient as free from ear noise and hyperacusis or classifies them into a risk group. Next, the patient is informed about the result and can then read about the causes of the ailment and the recommended treatment and also can download compressed sounds applicable in therapy to the rehabilitation tool coupled with the personal computer which is a programmable ear noise masker. In the paper the algorithm of analysis of patients answers and acoustic characteristics of tinnitus maskers are discussed. Hitherto obtained results of this method application are demonstrated.

Masking of tinnitus and mental activity.

The aim of this study was to investigate the effects of tinnitus on mental activity. In a mixed design study, the performance of 20 subjects with tinnitus and 20 healthy control subjects was compared on the digit-symbol test, completed in three auditory conditions: silence, masking and intermittent masking. Results showed marked overall differences between patients and controls on all three conditions. Lower scores on the digit-symbol test were observed during the intermittent masking condition compared with the masking condition for the patients. There was no difference between silence (e.g. tinnitus) and the masking condition, or between silence and the intermittent masking condition. The control subjects scored lower on the task when exposed to the intermittent masking compared to both silence and masking. The patients had higher depression and anxiety scores than the controls. These findings suggest that there is a link between masking sounds and how tinnitus affects cognitive capacity.

Prescription of binaural hearing aids in the United Kingdom: a knowledge, attitude and practice (KAP) study.

The purpose of this questionnaire study was to evaluate the existing knowledge of binaural hearing and the attitudes and practices of prescribing bilateral hearing aids amongst otolaryngologists in the United Kingdom. Of the 950 questionnaires sent to the current members of the British Association of Otolaryngologists and Head and Neck Surgeons (BAO-HNS), there were 591 respondents (62 per cent). The true response rate with completed questionnaires was 59 per cent. Eighty-one per cent of the respondents were aware of the importance of binaural hearing and had a positive attitude towards binaural fitting. The practice of bilateral hearing aid prescriptions was found to be poor amongst all grades on the NHS (less than 10 per cent of all hearing aid prescriptions). This practice in the private sector was variable, dependent largely on patient preference and affordability. The practice of binaural prescription was higher for patients in the paediatric age group than amongst adults. Two common indications for hearing aid prescriptions for unilateral deafness were otitis media with effusion in children (23 per cent of respondents) and for tinnitus masking in adults (12 per cent of respondents). Many otolaryngologists believed that there was not enough evidence to support bilateral bone-anchored hearing aid implantation and bilateral cochlear implantation. Ninety-four per cent of the respondents believed that binaural hearing was as important as binocular vision.

Tinnitus masking using ultrasonic signals

An apparatus for treating tinnitus involves generating a noise signal, by means of noise signal generator (10), to mask the ringing or buzzing in the ears caused by tinnitus and transposing the noise signal into the ultrasonic frequency range. As such, the masking signal effectively masks the tinnitus noise without interfering with the subject's perception of normal sounds such as human speech. In an alternative embodiment, human speech is transduced into electrical signals, transposed to the ultrasonic frequency range, and physically applied to the patient while tinnitus masking signals in the auditory range are applied to the patient.

Masking of Tinnitus through a Cochlear Implant

The relief of tinnitus has been effected in a cochlear-implant patient by presenting masking sounds to the microphone of the implant. Oddly enough, the presence of the masking sound improved the clarity of speech and music.

Psychoacoustic Measures of Tinnitus

This report reviews research from the 1930s to the present that has extended our understanding by investigating the characteristics of tinnitus that can be studied using psychoacoustic techniques. Studies of tinnitus masking and residual inhibition began in the 1970s, leading to the therapeutic use of tinnitus masking and a consequent increase in research devoted to tinnitus measurement. In 1981, the CIBA Foundation symposium on tinnitus advocated general adoption of four tinnitus measures: (1) pitch, (2) loudness, (3) maskability, and (4) residual inhibition. Since then, psychoacoustic research into all four topics has proliferated, yielding many valuable insights and controversies concerning the details of measurement techniques. A consensus has emerged that neither the loudness nor other psychoacoustic measures of tinnitus bear a consistent relation to the severity or perceived loudness of tinnitus. Nevertheless, quantification is needed in clinical trials of proposed treatments and in a variety of other types of tinnitus research. Standardization of techniques for specifying the acoustic parameters of tinnitus thus continues to be an important research goal.

Evaluation and selection of maskers and other devices used in the treatment of tinnitus and hyperacusis.

For more than two decades there has been a significant increase in the number and quality of studies investigating the phenomenon of subjective tinnitus. We mention subjective tinnitus because it is, by far, the most prevalent. Subjective tinnitus may be defined as the perception of an acoustic-like sensation for which there is no external generation. Objective tinnitus (vibratory tinnitus), on the other hand, is an acoustic-like sensation that can be heard by others and lends itself to physical measurement. Chronic myoclonus (chronic spasm of a muscle or of a group of muscles) involving the tensor tympani, stapedius and palatine muscles (referring to the palate), blood flow turbulence, and movement involved in the opening of the Eustachian tube are conditions that can cause objective tinnitus. Perhaps, one may include otoacoustic emissions as a form of objective tinnitus. This review will concern itself primarily with the rationale underlying the use of masker devices, hearing aids and other noise generating systems used in the treatment of subjective tinnitus. We review not only the phenomenon of tinnitus masking, but also discuss the use of controlled levels of noise in the treatment of hyperacusis, an exaggerated or abnormal intolerance to ordinary sounds in one's acoustic environment. In so doing, the emphasis is placed on the reader's understanding of each of the disorders, not only in terms of an applied external, acoustic stimulus but also of the individual's behavioral response to his or her malady. There are four messages for those contemplating the provision of clinical service to patients with subjective tinnitus. First, there is no consensus regarding the etiology of this perplexing disorder. Second, there is no known “cure” for subjective tinnitus. Third, there is no single therapeutic modality sufficiently compelling to warrant its use above all others. We are not suggesting individuals cannot be helped with some form of therapeutic intervention, including masker devices, but rather that there is much to be learned about the neurophysiological generation of subjective tinnitus and the psychodynamics of those who are suffering from it. Fourth, there is enough intellectual and clinical challenge in the treatment of subjective tinnitus to warrant the interest and active involvement of audiologists. Those working with the tinnitus patient deal with the symptoms of the disorder. The clinician can control to some extent the patient's awareness of the ongoing tinnitus through the use of masker or noise generating instrument(s), but can do nothing to affect a cure. To cure this perplexing problem, a way must be found to suppress the tinnitus generator(s), whatever it (they) may be, and thereby alter the abnormal neural activity which gives rise to its perception. The understanding of tinnitus and its treatment has advanced to that point where it is no longer necessary, or prudent, for the physician or any other health practitioner to advise the patient to “learn to live with it.” We say this, because there are a number of therapeutic approaches which have proven of significant benefit to the tinnitus patient, including masker and noise generating devices. Our task here is to review therapeutic practices and patient management strategies related to the use of masker devices and other noise generating systems. This review will include not only traditional masking, wherein the intent is to cover an aversive sound with a neutral one, but it will also discuss the use of combination hearing aid-masker instruments and masking tinnitus with hearing aids. Finally, it will consider retraining therapy, which has the intent not of covering the sound but rather of retraining the brain to ignore the sound so that it is no longer an issue in the patient's life.

Tinnitus masking and depression.

In this pilot study 30 patients with annoying tinnitus completed tinnitus matching and the Beck Depression Inventory (BDI). A cluster analysis revealed three clusters of patients. Cluster one had relatively low depression and average results on tinnitus parameters. Cluster two displayed high depression scores and lower results on tinnitus parameters. The last small cluster had high depression scores and high results on tinnitus and hearing parameters. A curvilinear regression showed a U-shaped relation between the BDI and minimal masking level. The results are interpreted according to a diathesis stress model, in which a vulnerable person might develop tinnitus distress following a comparatively low degree of tinnitus and a more stress-tolerant person might bear higher degrees of tinnitus before seeking help. As a conclusion this may have implications for what treatment to recommend and most certainly should be accounted for in the assessment of patients.

Effects of acclimatization and deprivation on non-speech auditory abilities.

This article reviews the evidence for acclimatization and deprivation with respect to non-speech auditory abilities. Although this subject has not been studied extensively, clear evidence exists for acclimatization and/or deprivation effects on intensity discrimination, binaural masking level difference, and auditory localization and lateralization. There is also some argument for such effects with regard to changes in tolerance for intense sounds or preferred levels of amplification. However, the main evidence for these effects, changes in loudness discomfort levels with repeated testing, may reasonably be explained as procedural or task-related effects rather than changes in auditory abilities. On the other hand, the successful use of tinnitus maskers to treat hyperacusis suggests that particularly low tolerance levels may be improved by exposure to certain types of auditory stimulation. Overall, this retrospective review of changes in non-speech auditory abilities, associated with the presence or absence of listening experience, indicates that acclimatization or deprivation effects may have influenced the results of some of the experiments reviewed. This suggests that experiments designed to study acclimatization or deprivation are timely and useful. In addition, acclimatization and deprivation are potential variables that should be considered, and preferably controlled, within experiments on auditory abilities. Clinically, the review adds weight to the argument for considering acclimatization and/or deprivation in hearing aid fitting and evaluation.

Minimum energy tinnitus masker

A tinnitus masking device and method for producing a masking signal with a selected center frequency, selected bandwidth, and selected volume is provided. A random noise generator and a clock circuit are employed in conjunction with a switched capacitance filter bank to produce a masking signal with the selected center frequency and selected bandwidth. The masking signal is then received by a volume control unit and then amplified for delivery to the tinnitus sufferer's ear or ears by speakers or headphones. Additionally, the tinnitus masking device may include a timer and fade out unit.

Neurophysiological model of tinnitus: Dependence of the minimal masking level on treatment outcome

Validity of the neurophysiological model of tinnitus (Jastreboff, 1990), outlined in this paper, was tested on data from multicenter trial of tinnitus masking (Hazell et al., 1985). Minimal masking level, intensity match of tinnitus, and the threshold of hearing have been evaluated on a total of 382 patients before and after 6 months of treatment with maskers, hearing aids, or combination devices. The data has been divided into categories depending on treatment outcome and type of approach used. Results of analysis revealed that: i) the psychoacoustical description of tinnitus does not possess a predictive value for the outcome of the treatment; ii) minimal masking level changed significantly depending on the treatment outcome, decreasing on average by 5.3 dB in patients reporting improvement, and increasing by 4.9 dB in those whose tinnitus remained the same or worsened; iii) 73.9% of patients reporting improvement had their minimal masking level decreased as compared with 50.5% for patients not showing improvement, which is at the level of random change; iv) the type of device used has no significant impact on the treatment outcome and minimal masking level change; v) intensity match and threshold of hearing did not exhibit any significant changes which can be related to treatment outcome. These results are fully consistent with the neurophysiological interpretation of mechanisms involved in the phenomenon of tinnitus and its alleviation.

Experiences in Kiel with the cochlear implant

Since 1988 22 deaf patients were provided with a 22-channel cochlear implant at the Kiel University Hospital. No surgical or postoperative complications were seen in any of the patients. Side effects like facial stimulation and pain sensation during electrode activation do not reduce the utility. Tinnitus may initially be severe but usually subsides to preop levels after a few days. A tinnitus masking effect is pronounced during stimulation but hardly lasts long after switch off. Besides an individually arranged hearing training the accurate speech processor fitting to the needs of the patient remains the cornerstone of successful rehabilitation. Objective intraoperative measurements such as the electrically evoked brain stem potentials and the middle ear reflexes yield estimates of the threshold values relevant for initial processor programming. Further information needed for the following extensive fine adjustment is obtained by subjective evaluation of loudness growth during electrical stimulation with variable parameters, by loudness scaling of narrow band noises with different middle frequencies and intensities presented under free field conditions and by speech audiometric procedures. The latter include a monosyllabic rhyme test and a logatom test developed at this institution. More speech testing is applied to document the degree of auditive rehabilitation. The results of speech tracking and the Freiburg tests as well as a new sentence test in silence and noise are discussed. In the multisyllable Freiburg test all but two of the adults understand the complete presented material, in the open set monosyllable test an average of 55% correct is achieved. Speech discrimination-oriented ranking showed 95% of all postlingually deaf patients in the highest performance category.

Recent Advances in Tinnitus.

Tinnitus can be the most debilitating symptom faced by people with hearing impairments. In the past 10 years, there has been a large increase in tinnitus research and in the development of clinical protocols. New animal models and physiological procedures provide an important contribution to the understanding and measurement of tinnitus. The annoyance of tinnitus likely depends on its loudness and the psychological makeup of the patient. The loudness of a person's tinnitus can be compared with the equivalent loudness of a 1000 Hz tone in a normal ear. Several questionnaires have recently been introduced to quantify the handicap caused by tinnitus. Tinnitus maskers are apparently ineffective for most patients but they can be helpful in a few patients. Medications are largely ineffective in reducing tinnitus in most people. However, several psychological techniques for reducing the stress associated with tinnitus are currently under investigation, and preliminary results show some promise. Tinnitus can be reduced by electrical stimulation in a few patients, and this is also an important area for future research.

Masking of tinnitus induced by sound.

Two experiments were performed in which 8 listeners used external sound to mask the tinnitus induced by a 95-dB SPL tone presented for 1 min. Wider bandwidth noises were more effective maskers than noises of critical bandwidth, which, in turn, were more effective than tonal maskers. Contralateral maskers were often effective, but less so than ipsilateral maskers. Tuning curves showed some degree of frequency specificity that was not related to the frequency of the tinnitus-inducing tone. There were consistent and pronounced differences between individual listeners. Overall, our results indicate both similarities and differences between the masking of induced tinnitus and the masking of pathological tinnitus.