Development and standardization of tinnitus handicap inventory in Nepali

Assessments of treatment outcomes
Table 3 shows comparisons of subjective (loudness, 
duration, annoyance, and THI) and objective (loudness 
matches and MML) tinnitus assessments according to 
Treatment parameters
TINI device
Laser type
Diode laser
Wavelength (nm)
830
Pulse rate
Continuous wave
Beam diameter (
μm)
600
Output power (mW)
100
Exposure duration sec)
1,200
Radiant energy [J] per treatment
120
Frequency of treatment (times)
10
Total radiant energy (J)
1,200
Application technique
10-15 mm distance from the 
tympanic membrane
Table 1. Laser treatment parameters.

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International Tinnitus Journal, Vol. 23, No 1 (2019)
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Table 3. Comparisons of tinnitus assessments over times in Sham and TINI groups.
Group
Baseline
Immediately after 
5-interventions
Immediately after 
10-interventions
Two weeks after 
10-interventions
x
2
p
*
 for 
time
p
†
 for post 
hoc analysis
Loudness (NRS, 0-10)
 
 
 
 
 
 
 
Sham
6.6 ± 1.8
5.6 ± 1.8
5.7 ± 2.0
5.7 ± 2.0
5.661
0.129
0.09
TINI
5.6 ± 1.9
5.6 ± 1.9
5.4 ± 1.8
5.5 ± 2.0
0.939
0.816
0.812
Duration (NRS, 0-5)
 
 
 
 
 
 
 
Sham
3.5 ± 1.0
3.11 ± 1.2
3.1 ± 1.2
3.2 ± 1.0
4.662
0.198
0.187
TINI
3.5 ± 1.0
3.5 ± 1.0
3.2 ± 1.2
3.0 ± 1.3
11.125
0.011
0.041
Annoyance (NRS, 
0-10)
 
 
 
 
 
 
 
Sham
6.3 ± 2.1
6.0 ± 2.4
5.3 ± 2.1
5.3 ± 2.2
5.216
0.157
0.127
TINI
5.6 ± 3.0
4.8 ± 2.6
4.8 ± 3.2
5.4 ± 2.8
6.467
0.091
0.621
THI (Questionnaire, 
0-100)
 
 
 
 
 
 
 
Sham
48.4 ± 
24.4
46.7 ± 22.3
44.2 ±22.0
43.4 ± 20.4
2.798
0.424
0.678
TINI
38.8 ± 
25.4
34.0 ± 28.3
33.9 ± 29.1
34.7 ± 28.2
3.85
0.278
0.248
Loudness matches 
(dB SL)
 
 
 
 
 
 
 
Sham
4.1 ± 8.2
Not measured
4.2 ± 7.2
3.0 ± 6.2
1.576
0.455
0.794
TINI
4.7 ± 6.9
3.4 ± 7.2
1.0 ± 4.7
6.818
0.033
0.058
Minimum masking 
level (dB SL)
 
 
 
 
 
 
 
Sham
-2.7 ± 
11.3
Not measured
-6.4 ± 6.5
-2.7 ± 9.6
2.457
0.293
0.953
TINI
-0.2 ± 
11.4
-2.53 ± 6.4
-2.2 ± 7.4
0.391
0.822
0.875
NRS: Numerical Rating Scale; THI: Tinnitus Handicap Inventory
*Friedman test
Post hoc analysis with Wilcoxon signed rank test between baseline and two weeks after 10-interventions; Data were expressed as mean ± 
standard deviation. Post hoc analysis was conducted with a Bonferroni correction applied, resulting in a significance level set at p<0.0125 (0.05/4) 
and p<0.017 (0.05/3) for subjective and objective tinnitus assessments, respectively. Bold indicates a statistically significant difference
treatment sessions in Sham and TINI groups. There was 
a statistically significant differences in perceived duration 
of tinnitus (x
2
(3)=11.125, p=0.011) and tinnitus loudness 
matches (x
2
(2)=6.818, p=0.033) depending on treatment 
sessions in TINI group. Perceived duration of tinnitus in 
TINI group decreased from 3.5 ± 1.0 to 3.0 ± 1.3 two 
weeks after 10-interventions. Tinnitus loudness matches 
in TINI group also decreased from 4.7 ± 6.9 dB SL to 1.0 
Variable
Sham (n=19)
TINI (n=19)
p value
Demographics
Age (years)
58.4 ± 11.8
53.3 ± 12.9
0.211
*
Sex (male:female)
11:08
16:03
0.074
†
Side (right:left)
09:10
08:11
0.744
†
PTA (0.5, 1, 2, and 4 kHz, dB HL)
48. 0 ± 21.4
39.1 ± 24.0
0.467
*
PTA (4 and 8 kHz, dB HL)
66.8 ± 18.4
62.4 ± 19.1
0.057
‡
Baseline subjective assessments
Loudness (NRS, 0-10)
6.6 ± 1.8
5.6 ± 1.9
0.172
‡
Duration (NRS, 0-5)
3.5 ± 1.0
3.5 ± 1.0
0.817
‡
Annoyance (NRS, 0-5)
6.3 ± 2.1
5.6 ± 3.0
0.583
‡
THI scores (0-100)
48.4 ± 24.4
38.8 ± 25.4
0.243
*
Baseline objective assessments
Pitch matches
5.0 ± 3.1
5.67±2.97
0.521
‡
<4kHz
5
4
0.390
¶
≥ 4kHz
14
15
Loudness matches (dB SL)
4.1 ± 8.2
4.7 ± 6.9
0.810
‡
Minimum masking level (dB SL)
-2.7 ± 11.3
-0.2 ± 11.4
0.365
‡
NRS: Numerical Rating Scale; THI: Tinnitus Handicap Inventory
Continuous variables were expressed as mean ± standard deviation; Independent t-test*, Pearson's chi-square test†, Mann-Whitney test‡, Linear-
by-Linear Association§, Fisher's exact test¶
Table 2. Demographic information of participants and baseline tinnitus characteristics.

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International Tinnitus Journal, Vol. 23, No 1 (2019)
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56
± 4.7 dB SL two weeks after 10 interventions. Despite 
on overall decrease in duration of tinnitus and tinnitus 
loudness matches in TINI group, there were no significant 
differences between the baseline and two weeks after 
10-interventions in post hoc analysis with Wilcoxon 
signed-rank tests (all p values >0.05).
Factors associated with treatment outcomes of 
tinnitus
Table 4 shows factors associated with treatment outcomes 
of tinnitus two weeks after 10-interventions compared to 
baseline. Respondents were defined as participants who 
improved the duration of tinnitus by at least one point or 
improved the tinnitus loudness matches by more than 5 dB 
SL. In the TINI group, respondents in duration of tinnitus 
were significantly older (p=0.044) and had significantly 
worse averaged pure-tone thresholds for 0.5, 1, 2, and 4 
kHz (p=0.010) compared to non-respondents. Similarly, 
respondents in tinnitus loudness matches in TINI group 
had significantly worse averaged pure-tone threshold for 
4 and 8 kHz (p=0.034) compared to non-respondents.
Safety
All participants tolerated the interventions without serious 
adverse effects. There was no observable damage to the 
external ear canal or tympanic membrane during or after 
LLLT.
DISCUSSION
This preliminary study evaluated the efficacy and safety of 
LLLT with new irradiation parameters (diode laser with an 
830 nm wavelength and an output level of 100 mw) for the 
treatment of chronic cochlear tinnitus. According to an 
animal study, only 5-6% of the output energy can reach the 
cochlea when an 830 nm wavelength is used
17
. One way 
to deliver more laser energy to the cochlea is to increase 
the output power of the laser. However, the increased 
irradiated light energy can result in damage to the external 
auditory canal, tympanic membrane, and inner ear
18
. 
Previous animal studies using 830 nm lasers reported a 
therapeutic effect of tinnitus at an output level of 165mw 
(total energy 2,376 J)
13
and demonstrated safety with an 
output level of 200 mW (total energy 5,040J)
18
. Thus, this 
study subjected participants to 100 mw of irradiation for 
20 minutes with a total of 10 interventions (total energy 
of 1,200 J). When comparing tinnitus assessments 
according to treatment sessions in the TINI group, there 
was a significant overall reduction in perceived duration 
of tinnitus and tinnitus loudness matches (Table 3). There 
was no statistically significant improvement of tinnitus 
in the Sham group. That is, there was no placebo effect 
to reduce the tinnitus. Although perceived duration of 
tinnitus in the TINI group significantly decreased from 
baseline by 0.5 after two weeks for LLLT (from 3.5 ± 1.0 
to 3.0 ± 1.3), there were no significant differences among 
different time points (baseline, during LLLT, immediately 
after LLLT, and two weeks after LLLT) in post-hoc analysis. 
Tinnitus loudness matches at pitch matching frequency in 
the TINI group also significantly decreased from baseline 
by 3.7 dB SL after two weeks for LLLT (from 4.7 ± 6.9 dB 
SL to 1.0 ± 4.7 dB SL). However, there were no significant 
differences among different time points in post-hoc 
analysis. The exact mechanism of tinnitus is still unclear, 
but hearing damage is thought to be the causal event 
in most patients
19
. Recent papers have demonstrated a 
cascade of changes in the central auditory pathway after 
cochlear damage, including enhanced spontaneous 
firing rates in various structures of the auditory system, 
tonotopic reorganization of the auditory cortex, and 
altered synchronous cortical activity. The logic behind 
laser-induced photochemical effects for treating tinnitus 
is its ability to restore the damaged inner ear (hair cells, 
afferent neuron etc.). In this study, participants who had 
improvements in perceived duration of tinnitus or tinnitus 
loudness matches two weeks after LLLT, had significantly 
worse pure-tone thresholds compared to participants 
who showed no improvement (Table 4). Previously, 
Dejakum et al.
20
applied medium-level (450 mW) laser 
therapy with the same wavelength (830 nm) to our study 
for chronic tinnitus
20
, but there was no therapeutic effect