Keywords
hearing - socioeconomic factors - child
Palavras-chave
audição - fatores socioeconômicos - criança
Introduction
When the sound is picked up by the external ear, it is detected by the inner ear and
then it passes through numerous cognitive and physiological processes so that the
decoding and understanding thereof can occur[1].
This system is challenged by the accurate coding task of the input sound. Auditory
information rises from the cochlea, along parallel paths, making a synapses on multiple
structures on its route towards the cortex[2]. These structures, together with the auditory cortex, are responsible for the physiological
mechanisms of hearing. Each of these mechanisms is associated with certain skills,
which will be more specific as it becomes increasingly necessary to detail the type
of sound stimulus[3]. So, the auditory processing refers to the effectiveness and efficiency which the
central nervous system uses the auditory information with[4].
Therefore, hearing is a part of a specialized system of communication, involving much
more than just peripheral sensitivity. This intricate sense involves the participation
of complex neuronal chains and higher mental functions to interpret verbal and non-verbal
sounds[5].
Thus, understanding the skills, abilities or capacities to deal with sound is possible
by observing the reactive behaviors of children and adults in the tasks to detect,
discriminate, recognize and understand the sound stimulus[3]
[6].
Special Tests were developed to evaluate the specific auditory skills, whether associated
or not with the alterations in communication, with the purpose of identifying an auditory
processing disorder[7]. One of the specific tests using the dichotic hearing task is the Dichotic Test
of Alternating Disyllable, as adapted by Borges for the Brazilian Portuguese (1986)[8], namely the SSW (Staggered Spondaic Word Test).
The SSW is an important tool to evaluate the process of dichotic listening. Thus,
knowing how this procedure can help understand the perceptual learning of speech becomes
important in speech therapy[7], since there may be a co-occurrence of auditory processing disorders and disorders
in speech, learning, and difficulties in reading and writing[9]
[10].
The importance of an stimulator environment for the correct development of the auditory
system and its skills is known. One factor that strongly influences the experiences
and the resulting cognitive stimulation of an individual from childhood to adulthood,
is the socioeconomic status[11]. The inappropriate stimulation, generated by both socioeconomic influences and family's
educational level, can contribute to delays in the child's overall development, refraining
motor skills, language and cognition from being acquired[12].
Therefore, the objective was to study the auditory skills evaluated by the Staggered
Spondaic Word Test - SSW - among schoolchildren aged between 7 and 10 years, from
different socioeconomic and cultural levels.
Method
The research is a part of the “Survey and Database on Hearing Health” project in the
Projects registered under No. 019731, approved by the Ethical Committee in Research
with a certificate No. 0138.0.243.000-06 on 05/12 / 2006. It was performed at the
Audiology Ambulatory of the Federal University of Santa Maria (UFSM)'s Phonoaudiological
Department Service (SAF), between November 2009 and October 2010, and it is characterized
as quantitative, cross-sectional, prospective and contemporary.
51 children aged between 7 years and 10 years and 11 months, coming from private schools
and public schools and/or philanthropic organizations serving needy children in the
city of Santa Maria/RS Were evaluated. The authorization of the schools was requested
by way of the Term of Institutional Authorization.
Individuals and their parents and/or guardians were informed about the objectives,
procedures, risks and benefits. Only children who consented to participate in the
research and who had the Term of Free and Clarified Agreement signed by parents and/or
guardians were evaluated.
The following aspects were used as selection criteria: air pure-tone audiometry thresholds
up to 25 dB at frequencies of 500 to 4000 Hz in both ears[13]; Speech Recognition Threshold (SRT) 6 dB above or below average of the pure-tone
thresholds of 500, 1000 and 2000 Hz[14]; Tympanometrry type A[15] and acoustic reflexes[16]; in addition to the absence of known neurological, cognitive, psychological and
hyperactivity disorders as well as articulatory and/or phonological changes that could
interfere with the repetition of the speech stimuli. The absence of articulation and/or
phonological changes was analyzed by an observational assessment during when the child
spontaneously spoke before the commencement of the tests.
Firstly, children's parents and/or guardians answered an anamnesis applied by the
researcher, who provided information about hearing disorders found at the time of
audiological evaluation, education, extracurricular activities and lifestyle habits.
After the anamnesis, the children passed by the visual inspection of the external
acoustic meatus and the tests of hearing thresholds, SRT and acoustic immitance audiometry
(AIA).
Evaluations occurred in an acoustically treated booth, using a Fonix - Hearing Evaluator - FA - 12, type I two-channel digital audiometer, and TDH-39P
Telephonics earphones. To obtain AIA, the middle ear Interacoustic Analyzer AZ7 used, the Telephonics TDH-39
p headset, Cochin MX-41, and a probe of 220 Hz to 70 dB NPS.
Parents and/or guardians of children also filled out a socioeconomic questionnaire
composed of two general questions, the first of which referring to items found at
home and the second referring to the level of education of the family's chief. This
questionnaire is a part of the Economic Classification Criteria of Brazil by the Brazilian
Association of Research Companies - ABEP (2008)[17], and it estimates the purchasing power of families.
To analyze the questionnaire, the scoring system was used for the items in each issue,
as described by ABEP. In the end, a calculation was made and each child's socioeconomic
status was obtained. The classifications of the questionnaire are: class A1, A2, B1,
B2, C1, C2, D and E.
No children in this study was classified as class A1 or class E. All children from
private schools were classified in classes A2, B1 or B2 were grouped together, therefore,
in Group 1 (G1). Children of public schools and philanthropic institutions were classified
in classes C1, C2 or D, and then grouped into Group 2 (G2).
The classification suggested by ABEP does not use a nomenclature for each class. In
order to assist in textual clarity and designation of groups 1 and 2, the terms medium-high socioeconomic level and medium-low socioeconomic level were used, respectively.
In addition to the socio-economic issue, the after-school activities undertaken by
the children, the family's leisure activities, as well as courses of foreign languages,
music (playing some musical instrument) and access to computer and/or Internet were
also taken into account.
After obtaining the anamnesis data, it was realized that the children classified under
G1 showed a big quantity and diversity of after-school and leisure activities, attended
foreign language and/or music courses and had access to the computer and/or the internet.
The children classified in G2 showed activities that were as simple as tours and activities
offered by the school itself, they attended no foreign language course, only one played
a musical instrument and those who had access to computers and/or the Internet did
so at relatives' houses.
In light of these observations, it was considered important to include the term cultural in the denomination of groups. It is believed that the different activities performed
by children may interfere with their development, and the most diversified activities
and access to different technologies can positively contribute to the individuals'
development.
Thus, the groups were named as such and established:
Subsequently, the Staggered Spondaic Word Test – SSW was applied.
Staggered Spondaic Word Test - SSW
The test created by Katz in 1962[18] and adapted to Portuguese by Borges in 1986[8] was applied as proposed by Pereira and Schochat (1997)[19]. It consists in the presentation of four sequences with 40 words each, presented
to the patient 50 dB above the three-tone average of the frequencies of 500, 1000
and 2000 Hz. These words are disyllabic paroxytones extracted from Brazilian Portuguese.
The SSW test is a procedure developed as a way of evaluating the central integrity.
It was presented with a Toshiba Digital-4149 Compact Disc Player coupled with the
audiometer described above.
It uses dichotic stimuli and the presentation of the sequences is as follows: the
first word is presented to the right ear without a contrasting message (right ear
not contrasting - RNC), two words are presented in both ears simultaneously (right
ear contrasting - RC and left ear contrasting - LC) and the last word is presented
without a contrasting message on the left ear (left ear is not competitive - LNC).
Before the start of the test, the child is guided about the task to be performed.
The child's task was to recognize and repeat aloud the four-word sequences that were
presented.
The responses of the 160 words were analyzed individually, and they were considered
right or wrong. Errors were regarded as: omission, replacement or distortion of the
word to be repeated. Inverting the word order in each sequence was also considered,
but not as an error.
SSW test results allow a quantitative analysis of the hearing condition and a qualitative
analysis of the types of errors. By a quantitative analysis to evaluate the hearing
abilities of back-figure for verbal sounds and by qualitative analysis, the ability
of temporal ordering of sounds is evaluated, among others[7].
For this study, the RC, LDC and total of right answers of the test were analyzed in
relation to the quantitative aspects and the order effect (OE), the auditory effect
(AE), inversions and Type A, in relation to the qualitative aspects.
For qualitative aspects, a classification of the type of errors was made when they
occurred outside the range of the expected limit[20]. So when AE is high-low and/or low-high OE, it is classified as a phonemic decoding; when low-high AE and/or high-low OE occurs, it is classified as gradual loss of memory; and when the number of inversions is higher than expected, it is classified as organization; and when the Type A is present, it is considered integration.
To classify normal and abnormal performance in the SSW test, the reference values
were considered by age group[21].
Data analysis
The descriptive analysis of the values was made, for which the calculation of the
arithmetic average, the standard deviation and the maximum and minimum points of the
variants in question was used.
To compare quantitative variants between the two groups studied, the Non-Parametric
Mann-Whitney U test was used for tackling two independent groups. As for the analysis
of qualitative variants, the independence Chi-Square test was applied.
The level of statistical significance was regarded as p <0.05 (5%).
Statistically significant results were marked with an asterisk (*) in the following
tables.
Results
In [Table 1], the results of the averages, minimum and maximum values, standard deviations (SD)
and the statistical analysis in relation to the conditions of contrasting right (CR),
contrasting left (CL) and the total of right answers in comparison of the groups 1
(G1) and 2 (G2) are shown.
Table 1.
Distribution of the number of individuals, averages, maximum and minimum values, and
standard deviations of the CR, CL conditions and the total of right answers for both
groups expressed in percentage (%).
|
Contrasting Right
|
Contrasting Left
|
Total of right answers
|
|
G1
|
G2
|
G1
|
G2
|
G1
|
G2
|
|
N
|
23
|
28
|
23
|
28
|
23
|
28
|
|
Average
|
74.7
|
66.7
|
73.4
|
64.7
|
82.2
|
76.6
|
|
Minimum
|
40.0
|
32.5
|
47.5
|
32.5
|
52.5
|
53.8
|
|
Maximum
|
97.5
|
90.0
|
97.5
|
92.5
|
97.5
|
90.6
|
|
SD
|
15.0
|
16.6
|
14.3
|
18.6
|
11.2
|
10.0
|
|
P
|
0.1055
|
0.1015
|
0.0497*
|
|
|
|
Mann-Whitney's U test
* Statistically significant difference (p < 0.05)
Legend: CR - contrasting right; CL - contrasting left; SD - standard deviation, P - p value.
In [Table 2], it is possible to observe the distribution of the number of children who have not
shown any changes in the quantitative variant, as well as those that did not fulfill
the expected CR and CL conditions in both groups.
Table 2.
Distribution of the number of children with and without a change in the SSW test in
relation to the quantitative variant of the groups G1 and G2.
|
Without change
|
Changed CR
|
Changed CL
|
Changed CR and CL
|
|
N
|
%
|
N
|
%
|
N
|
%
|
N
|
%
|
|
G1N = 23
|
5
|
21.7
|
4
|
17.4
|
1
|
4.4
|
13
|
56.5
|
|
G2N = 28
|
2
|
7.2
|
2
|
7.2
|
1
|
3.6
|
23
|
82.0
|
Legend: CR - contrasting right; CL - contrasting left.
In [Table 3], the results for the qualitative variant are shown, which was performed in accordance
with the trends of responses - OE, AE, inversions and Type A - based on the number
of children with typical results and changes in each group.
Table 3.
Exposure of the qualitative variants of the SSW test in relation to the number of
children with typical results and changes in the groups G1 e G2.
|
G1 (n = 23)
|
G2 (n = 28)
|
p
|
|
OE
|
|
|
0.0161*
|
|
Typical
|
16
|
10
|
|
|
Changed
|
7
|
18
|
|
|
AE
|
|
|
0.8432
|
|
Typical
|
17
|
20
|
|
|
Changed
|
6
|
8
|
|
|
Inversions
|
|
|
0.5104
|
|
Typical
|
16
|
17
|
|
|
Changed
|
7
|
11
|
|
|
Type A
|
|
|
0.1096
|
|
Typical
|
20
|
19
|
|
|
Changed
|
3
|
9
|
|
Chi-Square Test
* Statistically significant difference (p < 0.05)
Legend: OE: Order effect; AE: Auditory Effect.
In [Table 4], the classification of the type of error is shown according to the occurrence of
OE, AE, inversions and type A.
Table 4.
Classification of the type of error observed in the qualitative analysis for groups
G1 and G2.
|
Qualitative Analysis
|
Classification
|
G1 (N = 23)
|
G2 (N = 28)
|
|
Typical
|
39.1%
|
10.7%
|
|
High-low AE and/or
|
Decoding
|
21.7%
|
35.8%
|
|
Low-high OE
|
|
|
|
|
Low-high AE and/or
|
Gradual Loss of Memory
|
34.8%
|
57.2%
|
|
High-low OE
|
|
|
|
|
Inversions
|
Organization
|
30.5%
|
39.3%
|
|
Type A
|
Integration
|
13.0%
|
32.2%
|
Legend: AE - auditory effect; OE - order effect.
Discussion
This research, according to the objectives described above, studied the auditory skills
evaluated by the SSW test in schoolchildren of different socioeconomic and cultural
levels.
For the first analysis, relating to the quantitative aspects, there was a statistical
study in order to check differences between the two groups studied (G1 and G2) in
the conditions of contrasting right (CR) and contrasting left (CL) and the total of
right answers ([Table 1]). The analysis showed a statistically significant difference for the total of right
answers of the test but not for conditions of CR and CL.
Although there has been a statistically significant difference between groups in CR
and CL, it was found that the average results, as well as the maximum and minimum
values of the children of a medium-high socioeconomic and cultural level were above
those of medium-low level.
It is possible that the occurrence of a statistically significant difference in the
total of right answers was due to the participation of non-contrasting conditions
in its analysis, which usually have higher scores compared to competitive conditions[22]. This shows that the total score of the test, the children of the G1 showed superior
results compared to G2.
It was also verified, according to [Table 1], that the average results are below the normal range expected for the G1 and G2
and the G1 is beyond the results found for control groups in some studies[23]
[24]
[25] and G2 results are close to those found for children with learning disorders[25].
As the data shown in [Table 2], it can be observed that in both groups, fewer children had unchanged results in
the CR and CE. The vast majority had changes in both conditions. Among those who had
a change in only one condition, the CR prevailed. Although the incidence of children
with changes was observed in both groups, the incidence was higher in G2.
It was still verified that both groups had a higher percentage of correct answers
in the CR condition (G1: 74.7% and G2: 66.7%) in relation to CE (G1: 73.4% and G2:
64.7%). This finding corroborates with the findings in the literature[7]
[26], which demonstrated the superiority of the right ear in children at the SSW test.
In the second analysis, concerning the qualitative aspects, there was a tendency to
test responses (OE, AE, inversions and Type A), depending on the number of children
with typical results and changes ([Table 3]). The analysis found statistically significant only for OE.
However, as in the quantitative analysis, it was possible to observe that in the four
conditions analyzed, the number of children with a change was higher in G2 in comparison
with G1, as it can be seen in [Table 3].
A descriptive analysis of the qualitative variant was also performed (response tendency)
and then the classification was performed as proposed by Katz and Ivey (1994)[20], according to [Table 4].
The change in the category of phonemic decoding reveals processing problems in a phonemic level. These children usually have poor phonological
ability and difficulty in reading and spelling. There may also be a history of speech
problems in the first school years[27]
[28]. In G1, 5 (21.7%) children showed a change in this category, while in G2, the number
of children with a change increased to 10 (35.8%).
The classification of gradual loss of memory refers to two important features: difficulty in ignoring background noise, and immediate
memory. Educational performance is not as outdated as in individuals with problems
of decoding[27]
[28]. In this study, 8 (34.8%) children of G1 against 16 (57.2%) children of G2 were
classified in this category.
Those children falling into the category of organization have a great difficulty in organizing the information sequentially. Thus, the spelling
may be affected especially by reversing the order of letters[27]
[28]. In G1, 7 (30.5%) children were classified in this category and in G2, 11 (39.3%).
When the problem lies in the category of integration, the individual may be classified into two subtypes of problems. One is related to
the difficulties of visual auditory integration and severe reading and spelling disorders,
with a great phonetic deficit. The other subtype is less severe and its performance
is similar to individuals showing a gradual loss of memory[27]
[28]. Here, only 3 (13%) children of G1 and 9 (32.2%) of G2 were detected with a change
in this category.
This way, according to the classification of children in G1 and G2 verified in this
study, it can be affirmed that there is a greater number of children of medium-low
socioeconomic and cultural level showing problems in the categories presented. Generally
speaking, these results suggest, as a result, a higher educational deficit in this
group.
The kind of dysfunction that mostly occurred, contrary to the reviewed literature
that observed a higher incidence of the category of the decoding category[7]
[9]
[19]
[29], was the gradual loss of memory in both G1 and G2. That is to say, the greatest
difficulty lies in these children's auditory skills and figure-ground memory. The
difficulties related to the ability to extract acoustic tips in the auditory information,
recognition of auditory patterns and/or short-term memory influence the child's ability
to focus attention on certain tasks[30].
It is still important to mention that the categories are not mutually exclusive. The
same individual may be classified in more than one category.
In G1, out of the 23 children studied, nine (39.1%) were not classified in any category,
11 (47.8%) were classified in one, two (8.7%) children in two categories and only
one child (4.5%) was classified into three categories.
While in G2, out of the 28 children, only three (10.7%) had no classification as to
the categorization, 13 (46.4%) children were classified into one; 6 (21.4%) in two
categories and two (21 4%) children in 3 categories.
Thus, in G1, 13.2% of the children showed changes in more than one category, while
in G2, 42.8% of the children had this condition.
Therefore, the results show that in both groups there were children with changes in
quantitative and qualitative aspects of the SSW test. The fact that G1 children presented
a change ratio higher than expected, considering the advantage of a rich environment
to develop auditory stimuli, can be explained by the interference of other factors
influencing the results of this test, such as attention, the intellectual level and
linguistic load.
In addition, when evaluating skills associated with cognitive functions, such as auditory
skills, several factors can affect the results, turning the diversity of their responses
into something expected[31]. The literature highlights that, despite some results on tests of auditory processing
in children appear to be expressive, there is often a wide range between the tests
and individuals, which makes its interpretation difficult[32].
Specific studies that could compare the test results of the SSW test in children of
different socioeconomic levels were not found in the literature. However, by using
different methodologies and tests, researchers found few differences in auditory skills,
including skills of recognition, location, discrimination and sequential memory for
verbal and non-verbal sounds[33], selective attention[34]
[35], speech recognition in noise[36] and temporal resolution[5]. All showed the worst performance in children of lower middle-low level, concluding
that the socioeconomic and cultural development negatively interferes with the development
of the auditory processing.
It is known that the auditory processing has a key role in the development of speech
and language. Despite being separate clinical entities, they can co-exist[37]. The damage of auditory skills is related to changes in speech, reading and writing,
poor school and social performance[38].
Under all the analysis conditions of the SSW test: CR and CL conditions and qualitative
variants in accordance with the trend of answers- OE, AE, inversions and type A-,
better answers and a higher in G1 were verified; however, there was no statistically
significant difference for the total of right answers and OE only.
Conclusion
Based on the analysis and discussion of the achieved results, it was verified that
the hearing abilities evaluated by the SSW test in schoolchildren aged between 7 and
10 showed lower scores in children with a medium-low socioeconomic level in comparison
with those with a medium-high level.
Thus, the results suggest that the children with a medium-low socioeconomic level
have a higher discrepancy of the evaluated hearing skills, mainly of the gradual loss
of memory, and hence they are more susceptible to changes in speech and difficulties
in learning.
