Korean Version of the 12-Item Speech, Spatial and Qualities of Hearing Scale: Reliability and Validity in Adult Cochlear Implant Users
한국어판 12문항 Speech, Spatial and Qualities of Hearing Scale의 신뢰도 및 타당도: 성인 인공와우 사용자를 대상으로
Article information
Abstract
Background and Objectives
Patient-reported outcome measures are essential for evaluating real-world hearing performance in cochlear implant (CI) users. This study aimed to develop the Korean version of the 12-item Speech, Spatial and Qualities of Hearing Scale (K-SSQ12) and to evaluate its reliability and validity in Korean-speaking adult CI users.
Subjects and Method
The original English version of the SSQ12 was translated into Korean using standardized forward–backward translation procedures, followed by cultural adaptation, linguistic validation, and assessment of content validity. For psychometric evaluation, 56 adult CI users completed the K-SSQ12 twice, with a 2-week interval. Internal consistency was assessed using Cronbach’s α, test–retest reliability was evaluated using intraclass correlation coefficients (ICCs), and concurrent validity was examined by assessing correlations between K-SSQ12 scores and those of the Nijmegen Cochlear Implant Questionnaire administered concurrently.
Results
The K-SSQ12 demonstrated excellent internal consistency (Cronbach’s α=0.93) and high test–retest reliability (ICC=0.97). Significant correlations were observed between K-SSQ12 scores and the Nijmegen Cochlear Implant Questionnaire, supporting its concurrent validity with a CI-specific quality-of-life measure.
Conclusion
The K-SSQ12 demonstrated robust psychometric properties, with high reliability and good concurrent validity. It can be used to assess subjective hearing abilities and may serve as a valuable complement to standardized audiological assessments in clinical settings.
Introduction
Hearing loss can adversely affect communication across a wide range of listening environments and is associated with emotional distress, including depression, anxiety, and irritability, as well as social withdrawal and reduced participation in daily activities, ultimately impacting quality of life [1-3]. Hearing assistive devices, such as hearing aids and cochlear implants (CIs), are widely used in auditory rehabilitation, and their benefits are commonly evaluated using sound-field audiometry and sound-field speech audiometry [4].
However, these assessments are generally conducted under controlled listening conditions and may not fully capture the listening challenges, psychosocial consequences, and activity limitations experienced by individuals with hearing loss in everyday life. Consequently, the use of patient-reported outcome measures in conjunction with objective assessments has been increasingly emphasized to provide a more comprehensive evaluation of auditory rehabilitation outcomes [5].
Several standardized questionnaires have been developed to assess the self-perceived impact of hearing loss and hearing device use. For example, the Hearing Handicap Inventory for the Elderly (HHIE) [6] assesses socio-emotional difficulties related to age-related hearing loss, while the Abbreviated Profile of Hearing Aid Benefit (APHAB) [7] focuses on the perceived benefit of hearing aid use. The Attitudes Toward Loss of Hearing Questionnaire (ALHQ) [8] evaluates acceptance of hearing loss and attitudes toward amplification, and the International Outcome Inventory-Hearing Aid (IOI-HA) [9] measures overall satisfaction with hearing aid use. Although these instruments have been widely applied in clinical and research settings, most were originally developed for hearing aid users, which may limit their applicability to CI recipients [10].
The Speech, Spatial and Qualities of Hearing Scale (SSQ) [11] was developed to address this limitation by providing a comprehensive self-report measure applicable to both hearing aid users and CI recipients. The SSQ evaluates listening ability across three subscales, speech perception, spatial hearing, and qualities of hearing, and allows assessment of functional hearing in everyday situations. However, the original version of the SSQ consists of 49 items (hereafter referred to as SSQ49), which may be time-consuming to administer in clinical settings. To improve clinical feasibility, Noble, et al. [12] developed a 12-item short form (SSQ12) by selecting representative items from each domain, and its validity and efficiency have been demonstrated. The SSQ12 has been translated and validated in multiple languages, showing consistently high internal consistency and test-retest reliability [13-17]. Furthermore, the SSQ12 emphasizes more challenging listening conditions, enhancing its sensitivity to real-world listening difficulties.
However, a validated Korean version of the SSQ12 is currently lacking, and its reliability and validity have not been established in adult CI users. Given the distinct auditory characteristics of CI users, psychometric validation in this population is necessary to ensure clinical applicability. Therefore, this study aims to develop a Korean version of the SSQ12 (K-SSQ12) and to evaluate its reliability and validity in adult CI users. The study was conducted in two phases: 1) translation and cultural adaptation of the SSQ12 using a structured process, and 2) evaluation of internal consistency, test-retest reliability, and concurrent validity in a sample of adult CI users. The K-SSQ12 may provide a concise and clinically practical tool for assessing functional listening abilities in everyday environments among Korean-speaking CI users.
Subjects and Methods
Development phase
In the development phase, the original 12-item Speech, Spatial and Qualities of Hearing Scale (SSQ12) was translated into Korean, and its linguistic and cultural appropriateness was evaluated through a structured multi-step process. An overview of the SSQ12 and the procedures used to develop the K-SSQ12 are described below.
Overview of the measurement tool (SSQ12)
The original SSQ49 consists of 49 items and encompasses three primary domains (speech perception, spatial hearing, and quality) across ten subdomains (speech in quiet, speech in noise, multiple speech streams, speech in speech, localization, distance and movement, sound segregation, sound identification, sound quality and naturalness, listening effort) [11].
Although the SSQ49 provides a comprehensive assessment of functional listening abilities, its length may increase response burden and contribute to fatigue. A previous study has reported that participants with hearing loss require approximately 20 minutes to complete the SSQ49, with longer completion times observed among older individuals and those with greater degrees of hearing loss [18].
To address these limitations, the SSQ12 was developed as a shortened version consisting of 12 representative items selected to preserve the conceptual structure of the original instrument while improving clinical feasibility. The SSQ12 comprises the three main subscales (speech perception, spatial hearing, and quality) and covers nine pragmatic listening situations. Noble, et al. [12] demonstrated the structural validity of the SSQ12 by showing comparable response patterns to the SSQ49 in a large cohort of individuals with hearing loss. Subsequent studies have further reported high agreement between online and paper-based administrations of the SSQ12, supporting its use in both in-person and remote assessment contexts [17,19].
Instrument approval and translation procedure
Permission to translate and use the SSQ12 was obtained from the original author prior to study initiation. The translation and cultural adaptation process followed a five-step procedure based on the World Health Organization translation guidelines and established methodologies described in previous validation studies [20,21].
First, in the forward translation stage, two audiology researchers who were native Korean speakers fluent in English, along with one professional translator, independently translated the SSQ12 into Korean. The translated versions were reviewed and reconciled to ensure semantic equivalence and cultural appropriateness.
Second, a bilingual translator whose native language was English performed a back-translation of the reconciled Korean version into English. Three bilingual experts then compared the original English version, the Korean translation, and the back-translated version to evaluate semantic equivalence and conceptual consistency. Following established translation guidelines [22], particular attention was given to preserving the intended construct of each item (e.g., Item 10 assesses the ability to discriminate between different musical instruments rather than to identify their names). A linguistics expert further reviewed the Korean version for spelling and grammatical accuracy using standardized Korean language references.
Third, an expert committee review was conducted to assess content validity. Ten experts rated the relevance of each item using a 4-point Likert scale (1=not relevant at all to 4=highly relevant). The average content validity index for the K-SSQ12 was 0.95 (range: 0.83 to 1.00), indicating satisfactory content validity [23].
Fourth, pretesting and cognitive interviews were conducted with five adults with hearing loss to evaluate item clarity, potential semantic distortion, and cultural appropriateness. All participants reported that the items were clear and understandable, and no further revisions were required.
Finally, the results from all stages were integrated to finalize the K-SSQ12, which is presented in Supplementary Material.
Evaluation phase
Participants
A total of 56 adult CI users (16 males and 40 females) aged 18 years or older participated in this study. The mean age was 43.98 years (standard deviation [SD]: 13.86). Among them, 24 participants were bilateral CI users, 10 were unilateral CI users (right ear: n=6; left ear: n=4), and the remaining 22 were bimodal users who wore a hearing aid in the contralateral, non-implanted ear. The mean CI-aided pure-tone average across 500, 1000, 2000, 4000 Hz was 29.80 dB HL (SD: 7.97) for the right ear and 29.09 dB HL (SD: 7.27) for the left ear. The mean age at onset of hearing loss was 19.25 years (SD: 17.18), and the mean age at CI activation was 37.36 years (SD: 17.75).
At the time of the survey, none of the participants reported tinnitus, dizziness, or other otologic disorders. Prior to data collection, the purpose and procedures of the study were explained to all participants, and their participation was voluntary. Data were collected from October 8 to December 4, 2024, using an online survey platform (Google Forms). The same questionnaire was administered twice with a 2-week interval to assess test-retest reliability. The study protocol was approved by the Institutional Review Board of Hallym University of Graduate Studies (#IRB: HUGSAUD320915).
Measurement tools and procedure
K-SSQ12
The K-SSQ12 developed in the preceding phase was used as the primary self-report measure (Supplementary Material). The K-SSQ12 is structurally equivalent to the original English SSQ12 and consists of 12 items covering three major subscales (speech perception, spatial hearing, and quality) as well as nine pragmatic scales [12,14]. This structure allows for a multidimensional assessment of listening abilities in everyday situations among CI users.
Scores for the K-SSQ12 were calculated as the mean of item scores for each domain and as an overall mean total score. Of the 12 items, five items assess speech perception, three items assess spatial hearing, and four items assess quality. Each item was rated on a Likert scale ranging from 0 (“not at all”) to 10 (“perfectly”), with lower scores indicating greater perceived listening difficulty in the corresponding domain. Participants were allowed to select “not applicable” if they had not experienced the situation described.
Nijmegen Cochlear Implant Questionnaire
To assess concurrent validity, the Nijmegen Cochlear Implant Questionnaire (NCIQ) [24,25], was administered as a measure of health-related quality of life in CI users. The NCIQ consists of 60 items organized into three main domains (physical, psychological, social). These domains include six subdomains (Physical: basic sound perception, advanced sound perception, and speech production; Psychological: self-esteem; Social: activity limitations and social interactions).
Responses were rated on a 5-point Likert scale. Of the 60 items, 55 were rated from 1 (“never”) to 5 (“always”), while the remaining five items were rated from 1 (“very poor”) to 5 (“very good”). Participants could select “not applicable” for items that did not apply to them. A total of 27 items required reverse scoring, with lower scores reflecting greater difficulty or poorer quality of life in the corresponding domain.
Data analysis
All survey items were set as mandatory in the online questionnaire to minimize missing data. Statistical analyses were performed using SPSS version 25.0 (IBM Corp.). For item analysis, descriptive statistics including the mean, standard deviation, skewness, kurtosis, and corrected item-total correlation (ITC) were calculated for each K-SSQ12 item. Internal consistency reliability was evaluated using Cronbach’s α coefficient, and test-retest reliability was assessed using the Wilcoxon signed-rank test and the intraclass correlation coefficient (ICC). To examine concurrent validity, non-parametric Spearman rank-order correlation analyses were conducted between K-SSQ12 scores and NCIQ domain and subdomain scores. A significance level of p<0.05 was applied for all statistical tests.
Results
Item analysis
The results of the item analysis for the K-SSQ12 are presented in Table 1. The mean item scores ranged from 4.38 to 6.64. Skewness values ranged from -0.85 to -0.06, and kurtosis values ranged from -1.19 to 0.56. As the absolute values of skewness were below 1 and those of kurtosis below 1.5, the distributions of all items were considered acceptable [26].
Item analysis and internal consistency of K-SSQ12
The mean total score of the K-SSQ12 was 5.49 (SD: 1.73). Among the three subscales, the speech perception domain showed the highest mean score (5.67), followed by spatial hearing (5.39) and quality (5.33). The corrected ITC coefficients ranged from 0.52 to 0.84, indicating adequate item-total associations (≥0.30) for all items; therefore, all items were retained in the scale.
Reliability
Internal consistency
The Cronbach’s α coefficient for the total K-SSQ12 score was 0.93, indicating excellent internal consistency (Table 1). Removal of any individual item did not result in an increase in the α coefficient. Cronbach’s α values for the three subscales ranged from 0.78 to 0.92, demonstrating acceptable to excellent internal consistency across domains (speech perception: α=0.92; spatial hearing: α=0.86; quality: α=0.78).
Test-retest reliability
The test-retest reliability was evaluated by administering the K-SSQ12 twice with a 2-week interval. Wilcoxon signed-rank tests revealed no significant differences between the two administrations for any of the 12 items (z=-1.40 to -0.22, p>0.05). Similarly, no significant differences were observed for the subscale scores or the total score (speech perception: z=-0.88; spatial hearing: z=-0.38; quality: z=-0.55; total score: z=-0.31; all p>0.05).
The ICC for the total K-SSQ12 score was 0.97 (95% confidence interval: 0.94-0.98), indicating excellent test-retest stability. ICC values for the subscales ranged from 0.94 to 0.96 (speech perception: ICC=0.96, 95% confidence interval: 0.93-0.98; spatial hearing: ICC=0.94, 95% confidence interval: 0.89-0.96; quality: ICC=0.94, 95% confidence interval: 0.89-0.96), confirming high reliability across all domains.
Concurrent validity
Concurrent validity was examined by correlating K-SSQ12 scores with scores from the NCIQ. Descriptive statistics for the NCIQ domains and subdomains are presented in Table 2. Within the physical domain, the speech production subscale showed the highest mean score (82.42, SD=14.40), whereas the advanced sound perception subscale showed a relatively lower mean score (69.20, SD=17.96). Within the psychological domain, the self-esteem subscale had the lowest mean score (69.10, SD=20.73). In the social domain, activity limitations and social interactions showed similar mean scores (approximately 73 points).
Mean NCIQ score of each subdomain
Spearman correlation coefficients between the K-SSQ12 and NCIQ scores are presented in Table 3. All three K-SSQ12 domains (speech perception, spatial hearing, and quality) as well as the total score were significantly and positively correlated with all NCIQ subdomains (p<0.05). The speech perception domain of the K-SSQ12 showed moderate to strong correlations with NCIQ domains (rs=0.51-0.66), and the spatial hearing domain was also significantly correlated with all NCIQ domains (rs=0.34-0.62). The quality domain demonstrated significant correlations with all NCIQ subdomains (rs=0.41-0.67), particularly with basic and advanced sound perception. The total K-SSQ12 score showed significant positive correlations with all NCIQ domains (rs=0.50-0.71), supporting its concurrent validity with a CI-specific quality-of-life measure.
Spearman rho coefficients (rs) between K-SSQ12 and NCIQ
Discussion
In addition to objective audiological assessments, patient-reported outcome measures play an important role in evaluating listening abilities among individuals with hearing loss who use hearing assistive devices. In particular, for CI users, everyday listening difficulties and psychosocial consequences may not be fully captured by conventional objective measures alone, and the value of complementary self-report instruments has been repeatedly emphasized [27-29]. The SSQ12 was developed to address this need by providing a concise measure derived from the original 49-item SSQ. By selecting 12 representative items, the SSQ12 was designed to improve clinical feasibility while preserving the conceptual framework of the original instrument. In the present study, we developed the K-SSQ12 and evaluated its reliability and validity in adult CI users.
Item analysis indicated that all 12 K-SSQ12 items were adequately associated with the total score, with skewness and kurtosis values falling within acceptable limits. Among the three domains, mean scores were highest for speech perception, followed by spatial hearing and qualities of hearing. At the item level, relatively higher scores were observed for items related to sound quality in everyday listening and single-talker situations (e.g., Items 11, 1, 3, and 8). This pattern is consistent with previous findings reported by Mecklenburg, et al. [30], who identified Items 1, 8, and 11 as core items and suggested their potential utility as indicators of rehabilitation needs in CI users.
The K-SSQ12 demonstrated excellent internal consistency (Cronbach’s α=0.93) and test-retest reliability (ICC=0.97). These findings are consistent with those reported for other language versions of the SSQ12, such as the Arabic (α=0.94), Persian (α=0.92), and Romanian (α=0.97) versions [13,14,16], supporting the robustness of the Korean adaptation in adult CI users.
With respect to concurrent validity, K-SSQ12 domain and total scores showed significant correlations with multiple subdomains of the NCIQ, a CI-specific measure of health-related quality of life. In particular, the speech perception domain of the K-SSQ12 showed relatively stronger associations with the social interaction domain of the NCIQ, suggesting a close relationship between perceived speech understanding and social participation. In addition, the total K-SSQ12 score was significantly correlated with NCIQ domains related to sound perception, social interaction, and self-esteem, indicating that the K-SSQ12 captures aspects of listening ability that are relevant to broader quality-of-life outcomes. These findings are consistent with those of West, et al. [31] who reported parallel improvements and moderate correlations between SSQ12 and NCIQ scores following cochlear implantation. Although Mecklenburg, et al. [30] did not directly assess quality of life, their findings that SSQ12 scores were associated with self-rated satisfaction and confidence further suggest that the SSQ12 reflects dimensions extending beyond auditory performance alone.
An important strength of the SSQ12 is that it allows interpretation not only at the level of total and domain scores but also at the level of individual items and pragmatic listening situations, enhancing its clinical utility [22,30]. Mecklenburg, et al. [30] reported that item-level SSQ12 scores can inform the design of auditory training protocols. For example, when the score for understanding in multi-talker situations (Item 2) is markedly lower than that for single-talker situations (Item 1), training that targets listening in competing-talker environments may be warranted. Likewise, when scores on spatial hearing items (Items 7-8) are low, auditory training focusing on localization, directional discrimination, and perception of moving sound sources may be beneficial. In a longitudinal study of 1013 CI users, Wyss, et al. [32] reported mean improvements of approximately 2 points on both the SSQ12 and SSQ49, suggesting that the SSQ12 retains sensitivity to change despite its reduced length.
In addition to its role as an outcome measure, the SSQ12 has been explored as a potential screening tool for self-reported hearing difficulties. A recent Chinese validation study proposed a mean SSQ12 score of 6.0 as a cut-off for identifying individuals likely to have at least moderate hearing loss [33]. Although screening was not a primary focus of the present study, these findings suggest that the brevity and ease of administration of the SSQ12 may support its use in broader clinical or community-based contexts.
This study has several limitations. First, the sample size was relatively small (n=56), which may limit the generalizability of the findings and the ability to conduct more detailed analyses examining the influence of factors such as duration of hearing loss and length of CI use. Given the substantial interindividual variability in SSQ12 scores reported among CI users [30], future studies with larger samples are warranted to explore determinants of this variability. Second, the present study included only CI users, and therefore the findings cannot be directly generalized to users of other hearing assistive devices, such as hearing aids. In addition, discriminant validity could not be examined due to the absence of a normal-hearing comparison group. Third, test-retest reliability was assessed over a 2-week interval; longer follow-up periods would allow for a more comprehensive evaluation of the temporal stability of K-SSQ12 scores.
In summary, this study developed the K-SSQ12 and demonstrated its reliability and validity in adult CI users. The K-SSQ12 is a concise self-report instrument capable of capturing a wide range of everyday listening situations and provides a practical, time-efficient complement to objective audiological assessments. Its use may facilitate more comprehensive evaluation of listening difficulties and support individualized auditory rehabilitation planning for individuals with hearing loss in Korea.
Supplementary Materials
Korean translation of this article is available with the Online-only Data Supplement at https://doi.org/10.3342/kjorl-hns.2025.00577.
The Supplement is available with this article at https://doi.org/10.3342/kjorl-hns.2025.00577.
Notes
Acknowledgments
None
Author Contribution
Conceptualization: Seung Hwa Jeong, Jae Hee Lee. Data curation: Seung Hwa Jeong, Hae Na Kim. Formal analysis: Seung Hwa Jeong. Investigation: Seung Hwa Jeong, Hae Na Kim. Methodology: Seung Hwa Jeong, Jae Hee Lee. Supervision: Young-Myoung Chun, Jae Hee Lee. Writing—original draft: Seung Hwa Jeong. Writing—review & editing: all authors.