Keywords
tinnitus - fractal - music therapy - THI
Introduction
Tinnitus is a common, persistent symptom characterized by a sound sensation in the
“ears” or “head” that is not produced by mechanical-acoustic signals from the external
environment.[1] A recent epidemiological study based on 1,960 interviews conducted in the city of
São Paulo, Brazil, showed that 22% of the inhabitants had tinnitus,[2] a higher prevalence than the 10–17% value commonly reported in the literature.[3]
[4] We also observed that the prevalence of the symptoms increases progressively with
age and can be three times higher in the elderly (36% over 65 years of age) than that
in young adults (12%).[2] Many of the tinnitus sufferers also exhibited hearing loss and hypersensitivity
to sound.[5]
[6] Various pathophysiological causes underlie tinnitus, and all of the associated symptoms
interfere with evaluations of affected patients. For most patients, medical management
and appropriate counselling suffice; however, for other patients, the symptoms are
persistent and bothersome, and they interfere with daily activities and with the quality
of life. A recent U.S. study found that nearly a quarter of those who reported tinnitus
symptoms described it as disabling,[7] and according to Brazilian data, ∼ 34% of cases are severely annoying.[2]
The habituation theory[8] and the neurophysiological model of tinnitus proposed by Jastreboff in 1990 provided
new approaches for the clinical treatment of patients with tinnitus. Several therapeutic
approaches have been proposed based on these models, including TRT (tinnitus retraining
therapy), TAT (tinnitus therapy activities) and many other protocols that combine
counselling, sound therapy and relaxation.[9]
[10] These approaches combine sound therapy (as a facilitator) with procedures to habituate
the reactions caused by tinnitus and its perception, thereby resulting in a decreased
conscious perception of the signal. Sound therapy, such as sound amplification or
the use of sound generators, aims to decrease the contrast in quiet environments and
promote sound enrichment to facilitate habituation and provide partial or total masking
of tinnitus.
Currently, different forms of sound therapy are available, and several forms of stimuli
can be delivered from sound devices, which can be combined with amplification. Tinnitus
primarily occurs because of sensory deprivation and increased central neural activity.
A hearing aid can restore this system and is an effective treatment that has been
confirmed by several studies. Other studies have revealed that music has great therapeutic
potential for tinnitus relief.[11]
[12] Listening to music leads to relaxation and stress relief, both of which can contribute
to tinnitus control. In patients suffering from tinnitus, the presence of an annoying,
persistent, and uncontrolled out-of-context sound signal can increase stress levels
and cause an emotional disturbance that can exacerbate the perception of tinnitus.
Neuroimaging has revealed the brain structures involved in tinnitus perception, which
include the hippocampus, limbic area, frontal lobe, and cerebellum. These areas are
also highly activated when listening to music.[13]
[14]
[15] Music can be customized[16] and filtered in accordance with the individual's hearing loss and tinnitus pitch
and listening to pre-recorded music provides the patients with a structured listening
protocol.
Fractal tones are harmonic and melodic tones that sound like “wind chimes”; however,
because they are not predictable, these tones cannot be associated with any other
conventional music to which the patient may have been previously exposed. This unpredictability
is a unique and desirable feature of fractal tone music sound therapy because it induces
passive listening, which is required for habituation. Habituation represents a natural
brain function designed to reduce neutral stimulus perception under repeated exposure.
Recent studies have shown that the use of fractal sounds may represent a viable alternative
for minimizing the annoyance caused by tinnitus.[17] Fractal tones appear to lead the listener to a pleasant and relaxing auditory experience
and induce greater relaxation and stress relief compared with conventional music.
In an open-label clinical trial, 14 hearing-impaired adults with a primary complaint
of tinnitus were provided with one of several programs, including amplification only,
fractal tones only, and a combination of amplification, white noise and/or fractal
tones. Although the results did not show that the use of fractal tones was advantageous
over the other treatment protocols, the patients preferred listening to those tones
rather than noise over long periods. However, the role of fractal tones alone on chronic
tinnitus sufferers is difficult to determine based on the study reported above[17] because the report did not include the number of patients that used the fractal
device or amplification alone, and the results were too similar among the four studied
groups.
Music-based sound therapies have recently become a focus of tinnitus treatment because
they target two of the mechanisms that are assumed to underlie tinnitus: perception
and reaction. Such targeting has not been previously attributed to a white noise device.
The few publications that have studied the therapeutic use of fractal tones among
chronic tinnitus patients have rarely investigated the contribution of fractals separately
from other techniques, such as amplification, white noise, cognitive behavioral intervention,
and relaxation exercises.[17]
[18]
[19]
[20]
[21]
Objectives
The aim of this study was to determine the benefits of fractal tones as a unique sound
therapy for treating chronic tinnitus.
Patients and Methods
The study was conducted at the Tinnitus Research Group of the Otolaryngology Department
at the Clinical Hospital of the School of Medicine of Universidade de São Paulo. The
sample consisted of subjects with normal listening ability and tinnitus sufferers
who had mild hearing loss but no hearing loss complaints. These subjects were not
using any other treatment or medication during the investigation. The participants
were selected from August of 2014 to December of 2015, and they signed an informed
consent and agreed to participate in the study.
Inclusion Criteria
The inclusion criteria were as follows:
-
Normal listeners
-
Mild sensorineural hearing loss (no hearing difficulties) that did not exceed 40 dBHL
from 250 to 8,000 Hz
-
Chronic tinnitus that has persisted for more than 6 months
-
Tinnitus annoyance and handicap discomfort that are moderate, severe, or catastrophic
as measured by the Tinnitus Handicap Inventory (THI, which was translated into and
validated using the Portuguese language[22])
Exclusion Criteria
The exclusion criteria were as follows:
-
Pulsatile and/or somatosensory tinnitus
-
Patients with psychiatric disorders
-
Individuals with motor, visual and/or cognitive functions that prevent the implementation
of the procedures and the handling of hearing aids
-
Patients prescribed antidepressants, anxiety drugs or sleeping pills
-
History of drug abuse
Methods
This study was approved by the Ethics Committee of the School of Medicine – Universidade
de São Paulo - protocol number 611.174.
The participants were subjected to anamnesis, ENT (ear nose and throat) physical examination,
and a complete audiological evaluation, which included pure tone audiometry by air
and bone conduction at frequencies from 250 Hz to 8,000 Hz as well as speech audiometry
and acoustic immittance audiometry test measures. In addition to the audiological
evaluation, the participants underwent pitch and loudness matching and minimum masking
level (MML) measurements. These measurements were used to check for changes in the
perception of tinnitus before and after fitting the device. Many other studies, including
previous fractal studies, have not used psychoacoustic measures of tinnitus.[20]
[21] Our research team protocol uses these psychoacoustic measures routinely for all
patients on their first visit and after treatments, especially sound therapy. The
tinnitus impact and hearing handicap were assessed using the THI, HHIA (Hearing Handicap
Inventory for Adults)[23] and VAS (visual analog scale).
All subjects were administered instructional counselling at the beginning of the study.
Comprehensive information on the basic hearing anatomy and physiology, the tinnitus
etiology (that is, a natural consequence of hearing loss), the usual tinnitus course,
the strong relationships between hearing and emotions, the potential negative associations
with regard to hearing loss and the habituation process were also explained.
The fractal tones were delivered using MENU behind-the-ear hearing aids (Widex, Lynge,
Denmark). All participants were fitted with the devices in both ears, and all wore
them as open fittings, meaning that their ears were as open as possible to minimize
the effects of occlusion and physical discomfort.
Of the five available styles of fractal tones (one of the four Widex Zen program components),
the “Aqua style” was chosen because it was preferred by every participant during the
fitting session. Amplification was not provided. The participants were instructed
to use the device as frequently as possible and for at least 8 hours each day depending
on their level of comfort with the device. The participants were also instructed to
use the device during sleep. Adjustments to the fractal tones were performed by the
audiologist to ensure that the tones were audible in quiet environments and did not
interfere with conversational speech. To ensure that the device was used effectively
and guide the participants regarding the device's ability to control tinnitus perception,
we followed the participants for at least 6 months via individual counselling sessions.
The participants answered the questionnaires and were scored on the VAS scale at baseline,
1 month, 3 months and 6 months. The participants' hearing aid data log was checked
at the meetings to certify that the device was continually used. Tinnitus pitch and
loudness matching was performed before fitting and after 6 months of use.
The study involved[1] an audiologist, who was responsible for fitting the devices;[2] a physician, who was responsible for administering the clinical evaluations and
questionnaires; and[3] a second audiologist, who conducted all audiological tests and psychoacoustic measures
of tinnitus.
The variables sex, age, and time of tinnitus were described according to their frequency.
The quantitative variables (THI, VAS, pitch/loudness, and LMM) were described as means
and standard deviations (SDs). The statistical associations for each situation (before
and after device use) were compared using the Student t-test for quantitative variables, and the statistical significance was set at p < 0.05.
Results
Twelve participants were recruited, although six could not be assigned because they
were already taking medicine for tinnitus treatment or had another acoustic stimuli
preference. Four females and two males (mean age, 52 years; range, 34 to 70 years)
were enrolled, and five participants completed the data collection. [Table 1] shows the etiology in each case. Two participants complained of tinnitus in one
ear only, and the other four complained of a tinnitus sensation in both ears or in
their heads. All subjects had tinnitus for more than 1 year, and three had tinnitus
for more than 5 years. Although hearing loss had occurred in several subjects, it
was not a complaint and did not exceed 40 dBHL at any frequency. This finding was
confirmed by the HHIA scale instrument, which was used to determine hearing loss that
may represent a contributing factor to tinnitus annoyance. The HHIA score among almost
all participants was less than 12, indicating no hearing difficulties. In [Fig. 1], audiograms of our sample are presented.
Fig. 1 Audiograms of the six participants in the fractal study. Abbreviations: dB, decibels;
LE, left ear; RE, right ear; SDT, speech detective threshold; SHT, speech hearing
threshold; SRT, speech reception threshold.
Table 1
Etiology of subjects
|
Subjects
|
Etiology
|
|
1
|
Post-traumatic stress disorder
|
|
2
|
Metabolic syndrome
|
|
3
|
Endolymphatic hydrops
|
|
4
|
Otitis media
|
|
5
|
Idiopathic
|
|
6
|
Acoustic Trauma
|
The tinnitus pitch, loudness, and MMLs were measured at baseline. The mean pitch was
6,033 Hz (range, 500 to 11,200 Hz; SD, 4,462 Hz). The mean loudness was 9.8 dBSL (range,
5 to 21 dBSL; SD, 6.2 dBSL). The mean MML was 8 dBSL (range, 2 to 20 dBSL; SD, 6.3
dBSL). After 6 months of using the fractal tone device, all measurements were performed
again. Results showed a mean pitch equal to 5,240 Hz (range, 500 to 11,200 Hz; SD,
4,708 Hz), a mean loudness equal to 7 dBSL (range, 5 to 12 dBSL; SD, 2.9 dBSL), and
a mean MML of 7 dBSL (range, 3 to 15 dBSL; SD, 4.7 dBSL). None of the following measurements
showed significant improvements at the end of the treatment: pitch (paired t-test; two-tailed p value = 0.3739), loudness (paired t-test; two-tailed p value = 0.3796), and MML (paired t-test; two-tailed p value = 0.1302). The mean values, SDs and results are illustrated in [Table 2].
Table 2
Mean, standard deviation and loudness, pitch and minimum masking level values obtained
at baseline and after 6 months
|
VAS
|
Loudness[*]
|
Pitch[**]
|
MML[*]
|
|
A0
|
A6
|
A0
|
A6
|
A0
|
A6
|
A0
|
A6
|
|
Mean
|
7
|
5.6
|
9.8
|
7
|
6033
|
5240
|
8
|
7
|
|
SD
|
0.8
|
1.3
|
6.2
|
2.9
|
4462
|
4708
|
6.3
|
4.7
|
|
P
|
|
0.1087
|
|
0.3796
|
|
0.3739
|
|
0.1302
|
|
MSD
|
|
No
|
|
No
|
|
No
|
|
No
|
Abbreviations: A0, at baseline; A6, after 6 months of device use; MSD, mean significant
difference at p < 0.05; P, t-test p value; SD, standard deviation; VAS, visual analog scale.
* = measured in dBSL (decibels, that is, sensation level)
** = measured in Hz.
At baseline, the mean VAS score was 7 (range, 6 to 8), and after 6 months of treatment,
the mean VAS score was 5.6 (range, 4 to 7). Although a slight improvement was observed
for all subjects, the results were not statistically different (paired t-test, two-tailed p value = 0.1087).
The mean THI measured at baseline was 45 (range, 30 to 66), and the final THI was
25 (range, 18 to 30). A paired sample t-test showed that the 20-point difference was statistically significant (p < 0.05). The SDs, significant differences and confidence intervals are shown in [Table 3]. [Fig. 2] illustrates the measured values.
Fig. 2 Tinnitus handicap inventory scores measured before and after 1, 3 and 6 months of
fractal therapy. *, significant difference (p < 0.05).
Table 3
Mean, standard deviation and differences for the THI and its subscales at baseline
and after 6 months
|
THI
|
FS
|
ES
|
CS
|
|
A0
|
A6
|
A0
|
A6
|
A0
|
A6
|
A0
|
A6
|
|
Mean
|
45.17
|
25.60
|
18.17
|
8.40
|
17.7
|
10.80
|
9.83
|
6.40
|
|
SD
|
11.84
|
4.77
|
6.46
|
0.89
|
4.02
|
1.78
|
4.21
|
3.28
|
|
P
|
|
0.0136
|
|
0.0245
|
|
0.0579
|
|
0.0743
|
|
MSD
|
|
Yes
|
|
Yes
|
|
No
|
|
No
|
Abbreviations: A0, at baseline; A6, after 6 months of device use; CS, catastrophic
score; ES, emotional score; FS, functional score; MSD, mean significant difference
at p < 0.05; P, t-test p value; SD, standard deviation; THI, tinnitus handicap inventory.
The following three THI subscales were also analyzed: functional, emotional, and catastrophic
factors. All of these aspects improved after 6 months of treatment; however, only
the functional aspect showed a statistically significant difference. The results are
also shown in [Table 3] and [Figs. 2]–[3].
Fig. 3 Tinnitus handicap inventory functional, emotional and catastrophic scores measured
at baseline and after 6 months of fractal therapy. *, significant difference (p < 0.05).
Discussion
A self-reported survey using the 1999–2004 National Health and Nutrition Examination
Surveys (NHANES) database showed that more than 14,000 subjects among the U.S. adult
population reported having tinnitus. Among nine assessed tinnitus treatment methods
(hearing aids, music, medication, relaxation exercises, counselling, non-wearable
sound generators, herbs and dietary supplements, wearable sound generators, and psychological
counselling), substantial tinnitus amelioration was only observed for the treatments
with hearing aids (34%) and music (30%).[7] This finding was one of the motivations for our investigation into the effects of
music on chronic tinnitus sufferers.
The first report of the use of music for tinnitus management was published in 1988;
in this study, music and different types of tinnitus maskers were compared, and music
was recommended over traditional maskers for the first time.[24] However, music did not achieve widespread use as a form of sound therapy until recently.[16]
[25]
[26] Neuromonics is one of the first tinnitus music sound therapies to use pre-recorded
customized music (increased intensity) in accordance with the individual's hearing
loss and tinnitus pitch.[16] Another sound-based music technique is the tailor-made notched music training endeavor,
which presents an opposite approach to that of Neuromonics because it removes the
tinnitus frequencies and neighboring frequency regions from the music.[26] Fractal tones have a sound that is similar to wind chimes, and which can be processed
using an algorithm to create a melodic chain of tones that are sufficiently repetitive
to sound familiar and sufficiently varied to avoid predictability.[27] In addition, fractal tones emphasize certain musical elements, such as a slow onset,
slower tempo (near the resting heart rate of ∼ 60–72 beats/minute), lower pitch, repetition,
non-emotional content (to avoid evoking memories), and the combination of these elements
produce a soothing effect and heightened concentration in certain individuals.[28]
Thus, ENT doctors and audiologists can select from a wide variety of tinnitus music
sound therapy styles (for example, fractal tones, Neuromonics, tailor-made notched
music), although the styles that best suit each type of tinnitus patient are unknown.
Therefore, our aim was to verify the effectiveness of fractal tones on tinnitus perception,
annoyance, and magnitude among chronic tinnitus sufferers recruited from the Tinnitus
Research Group of the Otolaryngology Department of the Medical School at Universidade
de São Paulo. Patients with moderate, severe, or catastrophic chronic tinnitus, as
measured by THI, were selected. These patients had experienced a positive impact on
their quality of life but had not complained of significant hearing loss as measured
by the HHIA. Moreover, these patients were likely to benefit from sound therapy without
amplification because our goal was to verify the effect of fractal tones alone.
Among the excluded tinnitus patients, one was a musician who dropped out because due
to considering fractal tones to be annoying. This reasoning was consistent with the
results of a previous similar report[17] because a universal sound therapy that suits and works for all tinnitus patients
has not been identified, and certain types of music stimuli induce relaxation in some
individuals but not others.[28]
We followed most of the assigned patients for 6 months and others for 1 year. All
patients were instructed to listen to the fractal tones during waking hours, and our
data log analysis showed that the fractal tones were used for at least 8 hours per
day on average. The recommended time frame of 8 hours per day is inconsistent with
the recommendations in other studies, in which the recommended use of fractal tones
was only for 2 or 4 hours each day.[17] After a 6-month period, certain patients decided to keep the device because they
were using it throughout the day. However, other patients who did not observe considerable
improvements or tinnitus suppression stopped using the device continuously after the
end of the study. After the 6-month period, certain patients had worsened hearing
thresholds and were subsequently fitted with a hearing aid amplification, which represented
the best initial time point for selecting the combined hearing aid/sound therapy device.
During the study period, only the Aqua fractal style was used per the participants'
choice. This style was also the most preferred by participants in another study.[18]
After the sound therapy period, certain patients indicated experiencing a clinical
improvement in their daily quality of life, which included better concentration while
reading or studying and a greater ability to relax. Two participants used the device
to sleep because sleep problems were among their main complaints. All six participants
(100%) showed a clinical significant improvement in their THI scores, which decreased
by almost 20 points (the mean score at baseline was 45.1 and the mean score after
6 months of sound therapy was 25.6), and this finding is consistent with a previous
report in which a 30-point improvement in THI was observed.[20] Previous studies have indicated that 20-point THI score changes are clinically significant.[29] According to our data, the THI changes were only clinically significant at the final
appointment after 6 months of therapy. These findings are inconsistent with those
of previous studies in which an earlier response was observed at 2 months.[20]
[21] The authors applied the Zen therapy, which includes the four components: fractal
tones, broadband amplification, relaxation exercises and sleep management, in 24 and
19 assigned participants subjected to THI and TFI (tinnitus functional index) measurements,
respectively. In that study, the post hoc analysis based on a paired sample t-test showed a significant score reduction at 2 months, which indicated that earlier
tinnitus distress resolution and habituation could be achieved by the Zen therapy.
However, the authors used a simultaneous combination of tools, and the contributions
of each tool to the observed tinnitus improvement is unclear. Based on our results,
we aimed to determine the specific benefits of fractal tones for tinnitus sufferers
without combining it with other therapeutic strategies, and our instructions recommended
the use of this therapy for at least 8 hours each day.
In another study that was similar to ours,[30] the author investigated the effectiveness of fractal tones in patients with minimal
hearing loss by comparing two groups (n = 19/22) with the same tinnitus characteristics (THI > 18), and the control group
only received counselling. For 2 months, only fractal tones were employed in the study
group, although amplification was subsequently provided for those who had not been
responsive to fractal tones, and who indicated that they experienced hearing loss.
For those with normal hearing, other components of Widex Zen Therapy (WZT) were added,
such as cognitive behavioral therapy and relaxation exercises. Clinical and statistically
significant improvements were observed in the study group (21 points on the TFI) for
the first 2 months, and the patients continued to improve until the 6th month. The
author also investigated the long-term effects at 6 months after the end of the treatment
and verified that the participants who continued to use the device maintained the
benefits of treatment, whereas those who stopped using the device did not maintain
any benefits. This finding was also observed in several of our participants.
The THI is a 25-item self-reporting instrument that is grouped into three subscales
or domains. The functional subscale reflects limitations experienced by the patient
in mental, social/occupational, and physical functioning areas; the emotional subscale
includes a broad range of emotional reactions to tinnitus; and the catastrophic subscale
includes the destructive effects of experiencing tinnitus. We determined the subscales
or domains that were responsible for the THI score improvement after the 6-month fractal
sound therapy, and our results indicated that the primary result of this type of sound
therapy was a decrease in the scores on the THI functional scale, which measures concentration,
reading, attention, consciousness, sleep, social activities, and household tasks.
This finding was surprising and inconsistent with previous studies in which fractal
tones were reported to promote improvements in the emotional and catastrophic responses.[19]
[20]
[21] In our study, no statistically significant changes were observed in the results
for the THI emotional and catastrophic domains recorded at baseline and at the 6-month
evaluation.
The VAS, pitch and loudness matching, and MMLs showed a slight tendency toward improvement
in certain participants; however, our limited sample size precluded the detection
of clinically significant differences in these measures or any type of improvement
in the tinnitus magnitude after 6 months of fractal sound therapy. Because tinnitus
can exacerbate stress (and vice versa), relaxation and proper sleep schedules are
important for tinnitus patients, who are instructed to continue with their lives and
common routine. Although we did not expect to observe drastic changes in the psychoacoustic
measures, we did expect to observe changes in the participants' reactions to tinnitus
and the impact of tinnitus on their quality of life. These changes were detected by
the THI, which indicated that the greatest changes occurred in the functional domain,
as well as by the participants' spontaneous reports regarding improvements in their
attention and concentration.
Many different stimuli can be delivered by different devices used in sound therapy.
Such therapies can be applied in various strategies to control tinnitus. For example,
these therapies can be used to mask the tinnitus, avoid silence, diminish contrast,
thus facilitating tinnitus management. However, these therapies are not effective
for every patient, and the research remains inconclusive.
Tinnitus has different underlying causes; therefore, every patient and treatment strategy
are unique. Fractal tones are recommended as a sound therapy because this technique
clearly helped participants to concentrate and manage the associated distress, and
it facilitated sleep in certain participants.
We suggest that a combination of fractal tones with other elements, such as relaxation
techniques, will be beneficial for tinnitus sufferers.
The results of our study support the use of fractal tones as a sound therapy for tinnitus
patients. We also recommend future research on the long-term effects of this therapy.
Conclusions
We traced the individual contributions of fractal tones on chronic tinnitus sufferers
and found that the main benefit of this approach was in the THI functional domain,
which includes concentration, reading, attention, consciousness, sleep, social activities,
and household tasks. For all patients with bothersome chronic tinnitus who have high
scores on the THI functional scale, fractal tones should be considered as a good initial
sound therapy. The findings of this open-label pilot study are preliminary, and other
trials must be conducted before these results can be generalized to a larger tinnitus
population.
