Keywords
hearing loss - unilateral - hearing aids - questionnaires
Palavras-chave
perda auditiva unilateral - auxiliares de audição - questionários
Introduction
A unilateral hearing loss may be responsible for academic difficulties, speech or
language difficulties and social-emotional[1], is characterized by decreased hearing in one ear and occurs predominantly in males[2].
One study[3] was identified as major causes mumps, ototoxicity, meningitis, PAIR, chickenpox,
head trauma and unilateral hearing loss of unclear cause. The aplasia of the cochlear
nerve was considered the main cause of unilateral hearing loss in a retrospective
study of 480 children at a hospital in Philadelphia[4]. Recent data demonstrate the occurrence of a unilateral hearing loss for every 1000
live births[5].
The effects of unilateral hearing loss are smaller than those caused by bilateral
loss, however, in the presence of environmental noise individuals are more difficult
than the normal listeners to understand speech, even when the ear is better positioned
toward the talks. Furthermore, the spatial location of sound sources is compromised[6].
The location is affected because individuals with unilateral hearing loss do not have
the benefit of interaural time: when a sound comes from one direction, the time difference
and interaural phase differences of continuous sounds in both ears allows the individual
to determine which direction the sound is coming. The location favors the individual's
sense of security within your environment for mobility and communication; there may
be situations where the individual takes to locate the speaker, thereby losing the
message[7].
Humans are able to distinguish one sound source that has only two degrees of difference
from the horizontal plane and if it is located in front. The ability to determine
the direction of the sound source is based on the fact that sounds reach both ears
at the time, phase, intensity and / or different frequency. For continuous sounds,
the biggest clue to the location of the signal horizontal (right - left), frequencies
below 1500 Hz is the interaural time difference, presented in both ears, while the
biggest clue to the high frequencies is the difference interaural intensity and spectral
cues[8].
The hearing abilities for the perception and organization of the auditory environment
depend in part on the use of both ears and the result of interactions that occur between
neural signals and progress through binaural auditory pathway[9].
A person with unilateral hearing loss has difficulty understanding speech in noise
due to reduced binaural benefit: normal hearing in both ears helps the detection and
organization of speech in noise[10]
[11].
Individuals with difficulty in locating the sound source have lower speech recognition
in noise environments with competition increasing in them the sense of confusion and
loss of concentration[12].
The problems caused by sensory deprivation can be minimized with the use of hearing
aids Individual (HA), which allows the rescue of the perception of speech sounds,
beyond the environmental sounds, promoting improvement of communication skills[13].
This study aims to examine the benefit of hearing about the location during activities
of daily living in individuals with unilateral hearing loss from mild to profound
fitted with hearing aids Individual (HA).
Method
The procedures for selection and evaluation of the patients were started after approval
by the Ethics Committee (protocols 15/2007 and 297/2006) and signing the consent form.
This cohort study contemporary cross-sectional was conducted with 31 adults aged between
18 and 75 years and both genders (19 males and 12 females).
Inclusion criteria were that participants:
-
Age groups: adults and elderly (18-75 years).
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Hearing loss (HL) sensory neural, mixed or conductive to varying degrees.
-
Contralateral hearing within normal limits.
-
No experience with the use of hearing aids to first application of the questionnaire.
-
Effective use of hearing aids for at least six months for a second application of
the questionnaire.
The degree of hearing impairment was classified using the audiometric thresholds of
500, 1,000, 2,000 and 4,000 Hz: mild (average 26-40 dB HL), moderate AD (average 41-60 dB
HL) and severe (mean 61 80 dB HL) and depth (average above 81 dB HL), according to
WHO[14].
The data were collected to be identified as age, type and degree of hearing loss,
fitting time and daily use of hearing aids ([Annex 1]).
Anexo 1.
Protocol for data collection.
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Gender: ( ) F ( ) M
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Age: ___ years
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( ) With HA
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( ) Without HA
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Tipo de Perda Auditiva:
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( ) Conductive
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( ) Neuro sensory
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( ) Mixed
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Grau da Perda Auditiva:
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( ) Weak
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( ) Moderate
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( ) Severe
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( ) Deep
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Time of adaptation of the HA:
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( ) 6 months
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( ) 6 months to 1 year
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( ) 1 - 2 years
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( ) more than 2 years
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Time of daily use of the HA:
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( ) 2 - 4 hours
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( ) 4 - 8 hours
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( ) more than 8 hours
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Obs:
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|
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To evaluate the location of the sound source in daily activities, we used the Portuguese
version of the questionnaire validated by Ruscetta et al.[12]
The instrument consists of 14 questions related to the location of the sound source
in daily activities ([Annex 2]), applied individually by the same examiner on two occasions: with and without the
use of hearing aids.
Annex 2.
Questionnaire about difficulties and limitations associated with the location of hearing.
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1. You're at home in a quiet room. There are other people in the house. They are talking
in another room and you can hear them. You can tell which part of the house are these
people?
|
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1. ( ) Never
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2. ( ) Sometimes
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3. ( ) Usually
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4. ( ) Always
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2. You turn the wrong way when someone you cannot see you called?
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1. ( ) Always
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2. ( ) Usually
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3. ( ) Sometimes
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4. ( ) Never
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|
3. You're in a place that is unfamiliar. Someone you cannot see is pruning the grass
with the machine. You know where the sound is coming from?
|
|
1. ( ) Never
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2. ( ) Sometimes
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3. ( ) Usually
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4. ( ) Always
|
|
4. You're sitting around a table or at a meeting with several people. There is background
noise. You find it hard to know who are?
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1. ( ) Always
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2. ( ) Usually
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3. ( ) Sometimes
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4. ( ) Never
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5. You're in a house that is not familiar. It's quiet and suddenly hears a door slam.
You can tell which part of the house came the sound?
|
|
1. ( ) Never
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2. ( ) Sometimes
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3. ( ) Usually
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4. ( ) Always
|
|
6. You're in an apartment or an office building and hear a sound from another floor.
You can tell if the sound is coming from below or from the top of where you are?
|
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1. ( ) Never
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2. ( ) Sometimes
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3. ( ) Usually
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4. ( ) Always
|
|
7. You're on a sidewalk of a busy street. A car horn. Do you have trouble telling
which direction the car coming?
|
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1. ( ) Always
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2. ( ) Usually
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3. ( ) Sometimes
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4. ( ) Never
|
|
8. You are “out of doors” A dog barks loudly. You can tell where the dog without looking?
|
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1. ( ) Never
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2. ( ) Sometimes
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3. ( ) Usually
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4. ( ) Always
|
|
9. You're on the sidewalk of a busy street. You can tell which direction a bus or
a truck is coming before you see it?
|
|
1. ( ) Never
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2. ( ) Sometimes
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3. ( ) Usually
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4. ( ) Always
|
|
10. On the street, you can judge how far someone is from the sound of the voice or
the floor of that person?
|
|
1. ( ) Never
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2. ( ) Sometimes
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3. ( ) Usually
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4. ( ) Always
|
|
11. You're on the outside of a place that is unfamiliar. Someone called from somewhere
above you (like a balcony or a bridge). You find it hard to tell where the voice is
coming from?
|
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1. ( ) Always
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2. ( ) Usually
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3. ( ) Sometimes
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4. ( ) Never
|
|
12. You're on the sidewalk of a busy street. You can tell just by the sound, which
distance the bus or truck is?
|
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1. ( ) Never
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2. ( ) Sometimes
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3. ( ) Usually
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4. ( ) Always
|
|
13. You are the “outdoors”. You can hear an airplane. You think it's hard to say where
the plane is in heaven, only by the direction of the sound?
|
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1. ( ) Never
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2. ( ) Sometimes
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3. ( ) Usually
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4. ( ) Always
|
|
14. If you have difficulty locating the sound, would help you if you move to find
the direction of the sound?
|
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1. ( ) Never
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2. ( ) Sometimes
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3. ( ) Usually
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4. ( ) Always
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The questionnaire has four response options being “never” “sometimes,” “usually” and
“Always.” Each answer is assigned a value of one to four, to an alternative number
we adopted a weight (1) for alternative 2: weight two (2) for third alternative: weight
three (3) and Alternative 4: four weight (4). As the value 4 (four) indicating lower
degree of difficulty.
The subjects answered a questionnaire on the day that would be adapted to hearing
aids, ie without previous experience in the use of amplification and after the minimum
period of six months with the effective use of hearing aids the second session of
the questionnaire.
To perform the statistical study sample was divided into two groups and the G1 made
by individuals with hearing loss and sensory neural aged 44-75 years, and G2 comprised
of individuals with AD and mixed conductive and age group 18-43 years ([Table 1]).
Table 1.
Variable by separate groups for the Kruskal-Wallis.
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Variable
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Group 1 (G1)
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Group 2 (G2)
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Age
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18 - 43 years
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44 - 75 years
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Hearing loss degree
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Weak and Moderated
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Severe and Deep
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Time of adaptation of the HA
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6 months to 1 year
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More than 1 year
|
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Time of daily use of the HA
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2 to 8 hours
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More than 8 hours
|
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Hearing loss type
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Conductive and mixed
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Neuro sensory
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Results
The average response obtained in the questionnaire according to the type and degree
of hearing loss, fitting time and daily use of hearing aids were calculated
The statistical non-parametric sign test
[15] was used to identify a possible difference in auditory localization with and without
the use of hearing aids (minimum level of significance 1%).This test is based on the
median difference between the two situations: with and without hearing aids, if the
median is statistically equal to zero the two groups did not differ.
The non-parametric test of Kruskal-Wallis[15] aims to detect whether two or more independent samples are from the same population
or different populations. [Table 1] was applied to detect a possible difference in assessing the benefit to hearing
aid use for the variables: age, type and degree of hearing loss, fitting time and
daily use of hearing aids. To apply the test variables mentioned above were separated
into two groups. It was adopted minimum level of significance of 10% (p <0.10).
In [Table 2] are distributed to the averages of responses obtained in the questionnaire according
to the type and degree of hearing loss, fitting time and daily use of hearing aids
and age of individuals.
Table 2.
Averages of responses obtained in the questionnaire according to the type and degree
of hearing loss.
|
With HA
|
Without HA
|
|
Use time between 6 months and 1 year
|
3.17
|
1.90
|
|
Use time greater than 1 year
|
3.25
|
1.79
|
|
Sensory neural hearing loss
|
3.18
|
1.79
|
|
Mixed hearing loss / conductive
|
3.32
|
1.94
|
|
Degree of hearing loss weak / moderate
|
3.35
|
1.96
|
|
Degree of hearing loss severe / deep
|
3.05
|
1.67
|
|
Use time 2-8 hours / day
|
3.16
|
1.85
|
|
Use time more than 8 hours / day
|
3.26
|
1.83
|
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Aged between 18 and 43 years
|
3.31
|
2.06
|
|
Aged between 44 and 75 years
|
3.01
|
1.56
|
From the sign test was found statistically significant difference (significance level
less than 1%) for the results obtained in the questionnaire on the auditory localization
with and without hearing aids. The median estimate for the difference was 1.6 and
the confidence interval was (0.9, 1.8) ([Figure 1]).
Figure 1. Mean of scores on the questionnaire, with and without HA, according to the hearing
loss degree.
The Kruskal-Wallis test ([Table 3]) indicated no significant difference in benefit for the auditory localization between
G1 and G2 ([Tables 1] and [2]) according to the variables age, type of hearing loss, hearing loss, time the fitting
of hearing aids and daily use of hearing aids.
Table 3.
Statistics and H p-value computed for a Kruskal-Wallis.
|
Variable
|
Statistic H
|
p-value calculated
|
|
Age
|
1.51
|
0.22
|
|
Degree of Hearing Loss
|
0.02
|
0.88
|
|
Time Adaptation of HA
|
0.41
|
0.52
|
|
Time Use Diary HA
|
0.01
|
0.93
|
|
Type of Hearing Loss
|
0.05
|
0.82
|
Discussion
Whereas individuals with the same audiometric profile have different perceptions of
their problem and that the traditional audiometric tests provide only basic information
about the hearing abilities of the individual, it - is essential to assess the difficulties
of communication, location, social and emotional disabilities hearing through the
use of questionnaires[16].
The difficulty in locating sound can express in daily life situations. As regards
the distribution of responses obtained without the use of HA was observed that there
was difficulty in locating similar in different types and degrees of hearing loss
([Table 2]), and after the use of hearing aids for a minimum period of six months was a statistically
significant improvement for all variables considered, most notably the loss of mild
/ moderate. From these data we can observe that the difficulty increases as the hearing
sensitivity worsens.
The difference in time of reception of sound by two ears is what makes the first stimulated
ear indicating the direction of the sound source. Thus, a sound that originates, for
example, the right of a listener first come to the right ear, which is closer to the
sound source and, after a brief interval, reach the left ear, which is farther away[17].
As the results, you can see the benefit with the use of hearing aids for auditory
localization in accordance with the time of use and adaptation of the device, thus
the sensitivity of subjective measures, such as questionnaires, examining the progressive
improvement of listening skills, among them, the auditory localization in the period
that follows the adaptation of hearing aids it is important. In a retrospective survey
questionnaires given to parents of 20 children with unilateral hearing loss tailored
to HA were observed at 72% of positive responses regarding the benefit of it specifically
related to hearing ability in different environments[18].
Researchers performed an evaluation of the benefit of amplification in 29 individuals
with unilateral hearing loss by means of questionnaires Abbreviated Profile of Hearing
Aid Benefit (APHAB), Glasgow Hearing Aid Benefit Profile (GHABP), International Outcome
Inventory for Hearing Aids (IOI-HA) and Single-Sided Deafness Questionnaire. Improvement was observed in the localization of sounds after adjusting the sound
amplification device demonstrating the minimization of the head shadow effect. According
to the questionnaires used, after a year of monitoring individuals were satisfied
with the amplification[19].
Researchers who scored the biggest success of treatment of 57 subjects with unilateral
hearing loss with communication difficulties were related to higher early intervention
(surgery or amplification)[20].
Because the binaural hearing is a process, the brain, through the comparison of the
two auditory inputs can solve acoustic complexities, determine the direction of sound
and perfect a relevant signal in the presence of other sounds and noises[21]. According to the results we see that 61% of the sample made effective use of hearing
aids, using the same for more than eight hours daily and 39% 2-8 hours per day, thus
suggesting that the possibility of binaural hearing and consequently the ease of sound
location was significant in this population.
Thus, there is the importance of using these questionnaires, which makes it possible
to investigate the patient's perception about the difficulties of communication, helping
to monitor over time and identifying the real auditory needs beyond those possible
to be observed in the audiological assessment of routine[22]
[23].
Finally, the findings of this study showed the importance of research of the difficulties
imposed by unilateral hearing loss and rehabilitation benefits in these cases with
the use of amplification. The emergence of neonatal screening programs and early detection
of infants with this type of hearing loss that were previously neglected become imperative
that professionals are prepared for appropriate monitoring and intervention[24].
Conclusion
Benefits were observed on the auditory localization during activities of daily living
with use of hearing aids, and revealed that there was variability according to the
type and degree of hearing loss, duration of daily use and adaptation time of the
hearing aid.
