Keywords
reproducibility of results - hearing - surveys and questionnaires
Introduction
The Speech, Spatial and Qualities of Hearing Scale (SSQ) is a questionnaire designed
to assess auditory experience and quantify hearing disabilities in realistic communication
situations, with particular attention to binaural hearing. The questionnaire explores
the main aspects of hearing through 49 items organized into three domains measuring:
the capacity of the individual to listen to speech in different hearing contexts (Part
1—Speech Hearing); localization of sound events for different directions, distances
and movement (Part 2—Spatial Hearing); and the listening experience in relation to
segregating sounds, musical perception, clarity and naturalness of sounds, and listening
effort; (Part 3—Qualities of Hearing).[1]
The SSQ can be used to investigate small differences in binaural hearing ability and
has the potential for revealing the effects of different rehabilitation strategies
and technologies on auditory function. The original version of the SSQ 5.6 (49 items)
in English, the modified versions for application in specific populations, and adaptations
in different languages are available on a web site.[2]
The SSQ has been widely used in a host of different populations and languages with
studies showing its validity in clinical practice.[3]
[4]
[5] In Brazil, the scale has been translated and culturally adapted[6] using a four-step methodology: translation, back-translation, appraisal by expert
panel, and cultural adaptation.[7]
There is a growing demand by hearing rehabilitation professionals for more effective
tools. Essential features of a valid scale include high reliability and generalization
in different populations. Thus, to promote wider use of the Portuguese version of
the SSQ, the test-retest reliability of the scale must be investigated in hearing-impaired
individuals.
Therefore, the objective of the present study was to determine the test-retest reliability
of the Brazilian Portuguese version of the SSQ in adults with hearing loss.
Method
A prospective, clinical study was conducted at a teaching hospital following approval
by the local Research Ethics Committee (Permit CEP n° 273.023). The participants were
volunteers and gave consent for all procedures involved in the study.
The study sample included 35 individuals fluent in Brazilian Portuguese, without apparent
intellectual deficits and with acquired hearing loss. The group comprised 21 women
and 14 men with a mean age of 61 (SD 12.64) years and average education of 7 years
(SD 3.42). The mean hearing thresholds, based on the frequencies 500 Hz, 1 kHz, 2 kHz
and 4 kHz, were 44.29 dB NA for the best ear and 58.04 dB NA for the worst ear. Of
the participants, 71.4% exhibited sensorineural type and 28.6% mixed-type hearing
loss, while there were no cases of conductive hearing loss. No significant differences
in auditory thresholds were found between the best (44.29 dB) and worst (58.04 dB)
ears.
The participants answered questions on aspects of their hearing and listening capacity
and experience in different situations. The interviewer read each question out aloud,
ensuring that the patients were able to hear and understand the questions. The participants
rated their communication performance for each situation, assessed with a score of
0 to 10. It was explained to the subjects that 10 indicated they were able to perform
the situation in the question perfectly, whereas 0 indicated they were completely
unable to perform the situation. In addition, there was an option “not applicable”
for cases in which the question did not represent an everyday situation for patients.
The participants were then asked to explain why the question did not apply to them.
The Brazilian Portuguese version of the SSQ was applied by the same interviewer at
two time points, called test (1st interview) and retest (2nd interview), with both applications made in the morning. The interval between assessments
averaged 11 days.
The reproducibility of version 5.6 of the SSQ in Brazilian Portuguese was assessed
using Spearman non-parametric correlation. The correlation determined by this statistical
method denotes the degree of relationship between the test and retest of the scale
in the range 0 to 1. Internal consistency of the SSQ was measured by analyzing the
mean correlations among items based on Cronbach α coefficient. A significance level
of 0.05, or 5%, was adopted.
Results
The mean values for the two applications of the questionnaire differed only slightly.
The mean scores on the questionnaires showed a significant moderate-to-strong correlation
between test and retest. No significant correlation was detected between test and
retest for question 2 of Part I ([Tables 1], [2]).
Table 1
Descriptive analysis of indicators for the three domains (Parts I, II and III) and
general component of the SSQ at test and retest
|
Application
|
SSQ
|
Mean
|
Median
|
SD
|
Minimum
|
Maximum
|
|
Test
|
Part I
|
4.12
|
4.00
|
0.32
|
0
|
10
|
|
Part II
|
4.92
|
5.00
|
0.26
|
0
|
10
|
|
Part III
|
5.98
|
6.50
|
0.25
|
0
|
10
|
|
General
|
5.01
|
4.65
|
0.04
|
0
|
10
|
|
Retest
|
Part I
|
4.25
|
4.50
|
0.16
|
0
|
10
|
|
Part II
|
4.92
|
5.00
|
0.26
|
0
|
10
|
|
Part III
|
5.98
|
6.60
|
0.25
|
0
|
10
|
|
General
|
5.05
|
5.00
|
0.06
|
0
|
10
|
Abbreviation: SD, standard deviation; SSQ, speech, spatial and qualities of hearing
scale.
Table 2
Test-retest correlation by question on the Brazilian Portuguese version of the SSQ
scale (Spearman correlation)
|
Part I
|
Part II
|
Part III
|
|
Question
|
r
|
p-value
|
Question
|
r
|
p-value
|
Question
|
r
|
p-value
|
|
Q1
|
0.679
|
0.001
|
Q1
|
0.777
|
0.001
|
Q1
|
0.625
|
0.001
|
|
Q2
|
0.464
|
0.060
|
Q2
|
0.684
|
0.001
|
Q2
|
0.679
|
0.001
|
|
Q3
|
0.797
|
0.001
|
Q3
|
0.839
|
0.001
|
Q3
|
0.767
|
0.001
|
|
Q4
|
0.796
|
0.001
|
Q4
|
0.670
|
0.001
|
Q4
|
0.666
|
0.001
|
|
Q5
|
0.784
|
0.001
|
Q5
|
0.871
|
0.001
|
Q5
|
0.605
|
0.001
|
|
Q6
|
0.830
|
0.001
|
Q6
|
0.773
|
0.001
|
Q6
|
0.590
|
0.001
|
|
Q7
|
0.618
|
0.001
|
Q7
|
0.832
|
0.001
|
Q7
|
0.635
|
0.001
|
|
Q8
|
0.745
|
0.001
|
Q8
|
0.721
|
0.001
|
Q8
|
0.622
|
0.001
|
|
Q9
|
0.577
|
0.001
|
Q9
|
0.731
|
0.001
|
Q9
|
0.812
|
0.001
|
|
Q10
|
0.813
|
0.001
|
Q10
|
0.806
|
0.001
|
Q10
|
0.401
|
0.031
|
|
Q11
|
0.829
|
0.001
|
Q11
|
0.835
|
0.001
|
Q11
|
0.548
|
0.001
|
|
Q12
|
0.808
|
0.001
|
Q12
|
0.744
|
0.001
|
Q12
|
0.729
|
0.001
|
|
Q13
|
0.809
|
0.001
|
Q13
|
0.799
|
0.001
|
Q13
|
0.847
|
0.001
|
|
Q14
|
0.889
|
0.001
|
Q14
|
0.541
|
0.001
|
Q14
|
0.878
|
0.001
|
|
|
|
Q15
|
0.705
|
0.001
|
Q15
|
0.693
|
0.001
|
|
|
|
Q16
|
0.644
|
0.001
|
Q16
|
0.882
|
0.001
|
|
|
|
Q17
|
0.771
|
0.001
|
Q17
|
0.876
|
0.001
|
|
|
|
|
|
|
Q18
|
0.657
|
0.001
|
Abbreviation: r, correlation; SSQ, speech, spatial and qualities of hearing scale.
A significant strong correlation between test and retest of the SSQ was observed.
The responses of the participants for the three domains showed high reliability, indicating
that respondents provided similar answers at the two application time points ([Table 3]).
Table 3
Spearman correlation for test-retest by domain and general component of the SSQ
|
SSQ
|
No. of Items
|
Correlation
|
p-value
|
|
Part I
|
14
|
0.930
|
< 0.001
|
|
Part II
|
17
|
0.913
|
< 0.001
|
|
Part III
|
18
|
0.893
|
< 0.001
|
|
General
|
49
|
0.932
|
< 0.001
|
Abbreviations: Part I, speech hearing; Part II, spatial hearing; Part III, qualities
of hearing; SSQ, speech, spatial and qualities of hearing scale.
A significant strong correlation was found among all domains and for the 49 questions
([Table 4]).
Table 4
Cronbach α correlation by domain
|
SSQ
|
No. of Items
|
Correlation
|
p-value
|
|
Part I
|
14
|
0.952
|
< 0.001
|
|
Part II
|
17
|
0.945
|
< 0.001
|
|
Part III
|
18
|
0.822
|
< 0.001
|
|
General
|
49
|
0.932
|
< 0.001
|
Abbreviations: Part I, speech hearing; Part II, spatial hearing; Part III, qualities
of hearing; SSQ, speech, spatial and qualities of hearing scale.
Discussion
The analysis of SSQ scores revealed a similar result to those reported in other studies
in the literature for the hearing-impaired population.[1]
[8] By contrast, normal-hearing individuals tend to have higher scores ranging from
7.1 to 9.4.[6]
[9]
[10]
[11] Previous studies have shown a decline in SSQ scores with increasing hearing thresholds
by 0.43 to 0.69 points per 10 dB of hearing loss.[8]
[12] These findings suggest that the use of this instrument can reveal the problems caused
by hearing loss and screen individuals with or without hearing deficits.
A difference in performance was evident among the hearing domains assessed by the
scale, with lower mean scores on the speech-related domain (Part I) than on the spatial
(Part II) and qualities of hearing (part III) domains. Score disparities among the
subscales may be useful for assessing specific aspects of hearing disability.
In the present study, a significant correlation was detected between the different
items of the scale, with a high Cronbach α (0.932). The scales are self-report instruments
susceptible to random errors inherent to subjective assessments. The lower the occurrence
of such errors and the greater the stability of responses among items, the higher
the accuracy of the measurements and, consequently, the greater the reliability of
the instrument. Akin to results reported for normal-hearing subjects (0.946),[6] the Brazilian Portuguese SSQ showed good internal consistency in the hearing-impaired
population.
Two of the objectives of the present study were to examine the test-retest properties
of the Brazilian Portuguese SSQ and to determine the reliability of the instrument.
The results suggest that, for this sample, irrespective of the application time point,
the responses did not differ significantly for the three domains and general component
of the SSQ, evidencing good stability for responses. Analysis of the mean response
scores at test and retest by question (49 questions) revealed the occurrence of slight
differences in answers. Of all questions, only question 2 of Part I failed to exhibit
a significant correlation between test and retest, indicating greater variability
in responses between applications. The word “acarpetado” in Brazilian Portuguese is
believed to have attributed to the variation in answers on this question, given this
vocabulary is not commonly used in Brazil.
Cognitive aspects, age and educational level need to be further investigated in Brazil,
since these may influence the understanding of the questions and performance on the
SSQ, as previously reported in the international literature.[1]
[13]
[14]
[15]
[16]
Conclusion
The reliability indicators (test-retest and internal consistency) suggest good stability
of the Portuguese version of the SSQ, showing that the scale is suitable for use in
the hearing-impaired population in Brazil.
