A Study on Speech Perception and Health-Related Quality of Life in Adults With Partial Deafness and Severe-Profound Hearing Loss

Ⅰ. Introduction

Partial Deafness is a special type of sensorineural hearing loss, with a severe to profound impairment at frequencies above 1-2kHz and normal to moderately deteriorated hearing acuity at lower frequency bands (Cosetti & Waltsman, 2011; Skarzynski, 2012), with an audiogram akin to a ski-slope hearing loss (Skarzynski et al., 2006; Skarzynski et al., 2010). Adults with Partial Deafness have a relatively good audio-oral communication and support from lip-reading. However, noisy and multi-talker situations remain very challenging for this population (Cieśla et al., 2016). Often these patients remain beyond the scope of effective treatment with hearing aids only since amplification at frequencies above the region of substantial residual hearing provides little or no benefit for individuals with steeply sloping audiograms (McDermott & Dean, 2000). Therefore, one suggested, and successful treatment option for Partial Deafness is cochlear implantation (CI), including a combination of a cochlear implant and a hearing aid in one ear (electroacoustic system, EAS; Cosetti & Waltzman, 2011). Results suggest hearing preservation following cochlear implantation to allow for sufficient amplification in the low frequencies (Gantz & Turner, 2003; Kiefer et al., 2004). Speech results confirm the significant benefit of EAS, demonstrating a strong synergistic effect of combining the hearing aid and cochlear implant in the same ear, most particularly noted in noise (Gstoettner et al., 2004; Kiefer et al., 2004).

Skarzynski and colleagues reported that improvements in monosyllabic scores over time in both quiet and noise were significant, particularly within the first three months of Partial Deafness cochlear implantation use (Skarzynski et al., 2006). Another research showed that the length of the electrodes does not affect the degree of hearing preservation or speech understanding, and mean speech recognition in quiet was 30% before implantation and improved to 78.5% at 12months postoperatively (Skarzynski et al., 2019). Amoodi and colleagues evaluated a group of postlingually deafened adults, whose aided speech recognition exceeded commonly accepted candidacy criteria for CI. This group of patients demonstrates a significant improvement in speech and word recognition performance and hearing-related handicaps after CI (Amoodi et al., 2012). These results suggested that CI positively impacts on speech perception in adults with Partial Deafness.

Hearing impairment is not only a disability (a communication dysfunction) but can also be perceived by an individual as a handicap with its psychosocial effects. The extent of the handicap, however, cannot be predicted from the audiometric profile itself. It has been argued that behavioral and affective variables have to be considered to provide successful management of the disease (Cieśla et al., 2016). In recognizing the need to measure and objectify the benefits or limitations of medical interventions on an individual's social, emotional, and physical well-being, the term quality of life (QoL) has been defined (Loeffler et al., 2010). QoL is a broad-ranging concept, referring to an individual's perception of his/her position in life, affected in a multifaceted way by psychological state, level of independence, social relationships, personal beliefs, and physical health (World Health Organization, 1998). More specifically, this general health status of patients, often referred to as health-related quality of life (HRQoL), has been recognized as a more comprehensive measure of medical intervention outcomes (Mo et al., 2005).

Cochlear implantation does not only affect the hearing, speech perception, and speech production abilities of patients, but it also has a broader impact on social functioning, daily activities, and self-esteem (Hinderink et al., 2000; Hirschfelder et al., 2008). Therefore, in order to capture CI patient outcomes more holistically, the functional impact of permanent hearing loss and consequent treatment on personal well-being should be assessed through HRQoL measures (Capretta & Moberly, 2016). In recent years, in addition to standard speech perception testing, HRQoL has become a widespread outcome measure to quantify and monitor cochlear implant outcomes (le Roux et al., 2017). Hinderink and colleagues developed the Nijmegen Cochlear Implantation Questionnaire (NCIQ), which is a quantifiable, self-assessment HRQoL instrument for use in cochlear implant (CI) users. Validity, reliability, and sensitivity to clinical changes have been confirmed for the NCIQ. The data obtained with the NCIQ reflected that a CI had significant effects on several health-related QoL aspects, including the social and psychological domains (Hinderink et al., 2000). Chung and colleagues reported significant improvement of HRQoL even just one year after CI as categorically stratified by the SF-36 health questionnaire (Chung et al., 2012). The significant improvement between pre and post-implantation HRQoL scores was documented for unilaterally implanted postlingually (Mo et al., 2005; Olze et al., 2011), as well as prelingually (Straatman et al., 2014) deafened adult CI recipients. Similarly, HRQoL measures revealed a positive effect of implantation for postlingually deafened elderly patients (Orabi et al., 2006; Sanchez-Cuadrado et al., 2013), and also adult patients implanted for unilateral Deafness (Arndt et al., 2011; Vermeire & Van De Heyning, 2009). The results from the literature show that cochlear implants have a positive impact on speech perception and HRQoL among adults with Severe-Profound hearing loss.

Several studies on quality of life according to the onset of hearing have indicated that some authors suggest that underdeveloped communication skills at an early age can deteriorate emotional and social development (and potentially also neurological). On the other hand, others arguing that an altered identity from hearing to deaf in later-onset Deafness can be more detrimental to mental health (Øhre et al., 2011). Several large and medium population studies have indicated increased mental distress among patients with an acquired postlingual hearing impairment (with onset after developing language skills), as compared to the general population. Depressive/anxiety symptoms and social isolation were found most distinctive (Hallam et al., 2006; Kerr & Cowie, 1997; Kobosko et al., 2015). Findings concerning the correlation between audiological measures, such as pure-tone audiometry and mental health have been contradictory, probably since numerous factors can be contributed to the development of mental distress and a sensory impairment can be one of those (Øhre et al., 2011).

Adults with Partial Deafness are more likely excluded from CI candidacy, because they do not entirely fulfill the recommended audiological criteria, but they are still struggling with hearing aids. Our study was to examine adults with Partial Deafness in pre and post operative speech perception and HRQoL as compared to adults with Severe-Profound hearing loss to figure out the characteristic of adults with Partial Deafness and provide necessary information on counseling and rehabilitation for them. The specific research questions for this study are as follows.

First, did speech perception and HRQoL improve after cochlear implantation in adults with the Partial Deafness and Severe-Profound hearing loss?

Second, was there a statistically significant difference in speech perception and HRQoL between the Partial Deafness group and Severe-Profound hearing loss group?

Ⅱ. Methods

1. Participants

13 adults with Partial Deafness and 13 adults with Severe-Profound hearing loss participated in the study. All patients recruited to our study were patients in the Soree Ear Clinic between the years 2013 and 2018. All subjects complied with the following eligibility criteria: (1) the postlingual onset of Deafness (2) the duration of Severe-Profound hearing loss was less than ten years (3) the score of speech intelligibility rating (SIR) was 5 (4) without additional disabilities (5) had well developed verbal skills and used auditory-verbal communication. Only patients under the age of 61 were included to exclude the potential effect of hearing deterioration due to age (such as presbyacusis). Their aided thresholds were 25-35dB HL in the range of 250 to 4000Hz after CI.

Partial Deafness had low-frequency hearing (Pure tone threshold ≤65dB HL from 250 to 500Hz) and severe or profound hearing loss in the high frequencies (Pure tone threshold ≥70dB HL at 1500Hz). There were 3 male and 10 female subjects, and the mean age of patients was 41 years (SD=12.72; range 20-59yr).

Severe-Profound hearing loss is defined as a severe or profound hearing loss at all pure tone audiometric frequencies (>70dB HL at frequencies 250-8000Hz). There were 5 male and 8 female subjects, and the mean age of patients was 51 years(SD=9.03; range 36-61yr). Sociodemographic information on them is presented in Table 1.

Table 1.

Participants' information

Ⅲ. Results

1. Speech perception and HRQoL after CI

There were highly significant improvements in all three speech perception tests. Cochlear implant led to improvements in monosyllabic (t=-9.090, p<.001), disyllabic (t=-10.985, p<.001), sentence (t=-9.433, p<.001) in quiet, with the most improvement in the order of disyllabic word (59.3%), sentence (58.2%), and monosyllabic word (40.5%). CI resulted in a statistically significant increase in disease-specific HRQoL, as measured by the NCIQ, Cochlear implantation led to improvements in basic speech perception (t=-9.823, p<.001), advanced speech perception (t=-6.114, p<.001), speech production (t=-3.271, p<.01), self-esteem (t=-6.253, p<.001), activity limitation (t=-6.276, p<.001), and social interaction (t=-5.583, p<.001). In the HRQoL area, the most significant improvement was made in basic speech perception (46%), followed by activity limitation (33.9%), advanced speech perception (32.3%), self-esteem (32%), social interaction (29.3%), and speech production (13.6%) in order. The results are presented in Table 2 and Figure 1.

Table 2.

Comparison of speech perception and HRQoL between pre and post-CI

Figure 1.

Comparison of speech perception and HRQoL between before and after CICI=cochlear implant, BSP=basic speech perception; ASP=advanced speech perception; SP=speech production; SE=self-esteem; AL=activity limitation; SI=social interaction.

2. Adults with Partial Deafness vs. severe-profound hearing loss

Before CI, Partial Deafness group obtained significantly higher scores than those of the Severe-Profound hearing loss in monosyllabic (t=3.694, p=.001), disyllabic (t=4.403, p<.001) and sentence (t=5.604, p<.001). Furthermore, Partial Deafness group had significantly higher scores on the physical domain of NCIQ, basic speech perception (t=4.295, p<.001), advanced speech perception (t=7.356, p<.001), and speech production (t=3.925, p=.001). For the remaining scales of the NCIQ, self-esteem (t=1.179, p>.05), activity limitation (t=0.670, p>.05), social interaction (t=1.063, p>.05), no statistically significant differences were demonstrated between groups.

After CI, There were no significant differences in monosyllabic (t=0.647, p>.05), disyllabic (t=0.105, p>.05) scores between the groups. However, the Partial Deafness group obtained significantly higher scores than those of the Severe-Profound hearing loss in the sentence score (t=2.684, p<.05). Partial Deafness group had significantly higher scores on the physical domain of NCIQ, basic speech perception (t=2.569, p<.05), advanced speech perception (t=3.021, p<.05), and speech production (t=2.902, p<.05). No statistically significant between-group differences were demonstrated for the remaining scales of the NCIQ, self-esteem (t=0.778, p>.05), activity limitation (t=0.511, p>.05), social interaction (t=0.883, p>.05). The results are presented in Table 3, Figure 2 and 3.

Table 3.

Comparison of speech perception and HRQoL between groups

Figure 2.

Comparison of speech perception and HRQoL between groups before CIPD= partial deafness; Severe=severe-profound hearing loss; BSP=basic speech perception; ASP=advanced speech perception; SP=speech production; SE=self-esteem; AL=activity limitation; SI=social interaction.

Figure 3.

Comparison of speech perception and HRQoL between groups after CI

Ⅳ. Conclusion

In this study, the performance of the speech perception and Health-Related Quality of Life (HRQoL) of adults with Partial Deafness and Severe-Profound hearing loss was examined.

First, both groups showed statistically significant improvement in speech perception and HRQoL after CI. This means that CI has a positive effect on speech perception and HRQoL in adults with Partial Deafness and Severe-Profound hearing loss. In the speech perception, all three tests showed an average improvement of over 40%, with the most improvement in the order of disyllabic word, sentence, and monosyllabic word. In the HRQoL area, the most significant improvement was made in basic speech perception, followed by activity limitation, advanced speech perception, self-esteem, social interaction and speech production in order. This is consistent with the findings of Olze et al. (2011) that basic speech perception showed the greatest improvement in HRQoL. Hinderink et al. (2000) also reported that adults with Severe-Profound hearing loss showed the greatest improvement in basic speech perception and advanced speech perception after CI, and reported more than 30% improvement in the other four areas as well. This study is consistent in that the average of speech perception and HRQoL, excluding speech production, has improved by more than 30%. However, in this study, the speech production area alone showed less than 15% of improvement, which appears to have been affected by the fact that this study included adults with Partial Deafness, whereas only adults with Severe-Profound hearing loss were targeted in the study of Hinderink et al. (2000). The adults with Partial Deafness of this study showed that the average of their speech production area before CI already indicated 86.8% satisfaction, which can be interpreted as their quality of life in terms of speech production even before CI has affected the degree of improvement in post-operative scores.

Second, as a result of analyzing the difference between the adults group with Partial Deafness and the adult group with Sever-Profound hearing loss on speech perception and HRQoL, the Partial Deafness group showed significantly higher performance than the Severe-Profound hearing group in all monosyllabic, disyllabic word, and sentence speech perception tests before CI. In terms of HRQoL, the Partial Deafness group showed significantly higher performance than the Severe-Profound hearing loss group in the basic speech perception, advanced speech perception, and speech production areas corresponding to physical functions. However, there were no statistically significant differences between the two groups in the areas of self-esteem, activity limitation, and social interaction. This means that the adults with Partial Deafness have relatively low HRQoL satisfaction compared to their speech perception performance, and that the subjective satisfaction level of adults with Partial Deafness who feel on their own in terms of psychological and social functioning is similar to the adults group with Severe-Profound hearing loss. This is consistent with the study of Amoodi et al. (2012), who reported that adults with post-lingual hearing loss with a HINT score of 60% or higher showed acceptable levels of performance on objective speech perception test conducted in quiet situations, but subjectively felt as difficult as CI subjects. These findings suggest that the HRQoL evaluation can be an important measure when considering CI subjects, and that evaluations should be made for the characteristics of each hearing loss type.

Both groups also showed degraded quality of life in the psychological and social functioning of HRQoL before CI. Looking into the study participants' average quality of life on psychological and social area of HRQoL before CI, it is interpreted that both groups, shown with 35 to 40 percent by adults with Partial Deafness and 27 to 31 percent by adults with Sever-Profound hearing loss, suffer from health-related self-esteem, participation in activities and social interaction. In fact, the psychological evaluation conducted by Soree Ear Clinic showed that over 70% of the participants complained of psychological difficulties such as depression, inferiority, and anxiety in the BDI (Beck Depression Inventory), SCT (Sentence Completion Test), and MMPI-2 (Minnesota Multiphasic Personality Inventory-2) tests. This is consistent with the pilot study in which the adults with Partial Deafness and Sever-Profound hearing loss showed significantly more psycho-pathological symptoms, such as depression and anxiety, and significantly lower health-related quality of life compared to adults with normal hearing (Cieśla et al., 2016; Fellinger et al., 2007; Hallam et al., 2006; Kerr & Cowie, 1997). Given that both groups are post-lingual hearing impairment adults, study compared with adults with pre-lingual hearing loss showed that post-lingual Partial hearing impairment adults indicated significantly lower satisfaction than adults with pre-lingual Partial hearing loss in the areas of NCIQ activity limitation and social interaction in Cieśla et al. (2016). While adults with pre-lingual Partial Deafness develop ways to cope with adjusting to corresponding effective communication strategies due to the lifetime experience of disability (Øhre et al., 2011), post-lingual hearing impairment adults tend to experience confusion and anxiety as they suddenly lost their fluent audio-verbal communication ability as a result of hearing loss. Consequently, it is highly likely that post-lingual hearing loss patients are not engaged in social participation (Kerr & Cowie, 1997; Luey et al., 1995). Thus, both groups urgently require speech perception and communication recovery through CI, and in addition, it suggests that they need social support such as interaction with groups that can share psychological support for them and sense of homogeneity before CI.

After CI, there was no statistically significant difference in monosyllabic and disyllabic word speech perception between Partial Deafness adults group and Severe-Profound hearing loss adults group. However, the performance of Partial Deafness adults in the sentence was significantly higher than Sever-Profound hearing loss adults. One possible explanation for the above result is the use of 'low-frequency hearing'. In this study, only the speech perception of the CI ear was examined during the speech perception test. Consequently, it is interpreted that adults with Partial Deafness may have utilized the residual hearing of the CI ear in the sentence speech perception test. As the residual hearing in Partial Deafness adults group of this study was shown in 5 patients with complete hearing preservation and 8 patients with Partial hearing preservation, they were able to utilize residual hearing even when the other ear was blocked. Low frequency sounds below 500Hz are frequencies that convey suprasegmental elements and vowel, such as melodies of speech, rather than individual speech sounds/phoneme (Kramer, 2014), which affect sentence perception rather than words. Therefore, the improvement of operative technique that preserved the residual hearing of the CI ear and the opposite ear as much as possible, and the wearing of aid equipment that can utilize the residual hearing will have a positive effect on the sentence speech perception of adults with Partial Deafness.

When comparing HRQoL of two groups after CI, the Partial Deafness group, as in the pre-operative results, showed significantly higher performance than the Severe-Profound hearing loss group in the basic speech perception, advanced speech perception, and speech production areas, which are the physical functioning of HRQoL. In other words, after CI, there was no significant difference between two groups in monosyllabic and disyllabic word speech perception tests except for sentences, but it means that the hearing-related quality of life was higher in adults with Partial Deafness than adults with Severe-Profound hearing loss. While the speech perception test in this study is an evaluation conducted in a limited space such as a quiet situation and a test room, the physical functioning of HRQoL is to evaluate the hearing-related quality of life in daily life. Accordingly, this can be interpreted that adults with Partial Deafness who can utilize low frequencies show higher satisfaction in real situations where noise situations or conversations between multiple talkers are required. The result of comparing the differences between the two groups in the psychological and social functioning of HRQoL found that the Severe-Profound hearing loss group's scores of self-esteem, activity limitation and social interaction tended to be lower than Partial Deafness group on average, but there was no significant difference between the groups. This is consistent with Kobosko et al. (2018)'s study that the comparison of self-esteem in four groups, which include patients with pre-lingual Partial Deafness, patients with pre-lingual severe-profound hearing loss, patients with post-lingual Partial Deafness and patients with post-lingual severe-profound hearing loss. They showed that the self-esteem of patients with post-lingual severe-profound hearing loss was weakest. However, the self-esteem of patients with post-lingual Partial Deafness and patients with post-lingual severe-profound hearing loss did not show statistically significant differences between the two groups. These results indicate that adults with Partial Deafness have a significantly higher quality of life satisfaction than adults with Sever-Profound hearing loss in the physical functioning of HRQoL. However, it means that the Partial Deafness group's quality of life in psychological and social functioning is similar to that of Sever-Profound hearing loss group.

Both groups score around 60% of their psychological and social function after CI. These results indicate that unilateral CI is not a perfect alternative for improving psychological and social quality of life for adults with post-lingual Deafness, and it suggests the need for follow-up studies on factors affecting the overall improvement in HRQoL satisfaction of adults with hearing loss as per hearing characteristics. In this study, among hearing loss whose HRQoL total score and each sub-area score were 80% or more after CI, P10 was the only patient with Partial hearing loss who received simultaneous bilateral CI in both ears. According to her actual report, she could hear sounds on both sides, so she had a little difficulty when she was in noisy places or talking with several people. This is consistent with the results of Olze et al. (2012), who reported that the speech perception scores correlated significantly with HRQoL in bilateral CIs rather than unilateral CI. Therefore, further research is needed to determine whether bilateral CIs could be an alternative for improving HRQoL in adult CI subjects.

Taken together, the results of this study showed significant improvements in both speech perception and HRQoL sub-areas after CI for both adults with Partial Deafness and adults with Severe-Profound hearing loss. This confirmed that as well as adults with Severe-Profound hearing loss, adults with Partial Deafness who have a relatively high sentence speech perception score in a quiet situation could also receive positive help in the overall area of HRQoL with improved speech perception through CI. The results of analyzing the differences between groups in speech perception and HRQoL found that adults with Partial Deafness showed significantly higher performance than Sever-Profound hearing loss group in speech perception tests and HRQoL's physical functioning before CI. However, they indicated similar quality of life characteristics as adults with Severe-Profound hearing loss in psychological and social function. This means that, despite their relatively good speech perception ability, adults with Partial Deafness show the quality of life felt by adults with Severe-Profound hearing loss in psychological and social functions. After CI, there was no significant difference in word speech perception between two groups, but the sentence score of adults with Partial Deafness was significantly higher. It is interpreted that Partial Deafness adults' residual hearing has a positive effect on sentence perception. After CI, adults with Partial Deafness showed significantly higher performance in HRQoL physical function as pre-operation, but there was no significant difference in psychological and social function between the two groups. Both groups showed about 60% satisfaction in psychological and social function after CI. Consequently, after CI, it is necessary to develop an intervention program that can improve their psychological and social satisfaction, and carry out follow-up studies on factors affecting their HRQoL improvement. The results of this study suggest that HRQoL can be an important criterion for the selection of CI subjects, and assessment tools to sensitively evaluate the performance of adults with hearing loss for each hearing type should be prepared.

Acknowledgments

This article was based on the first author's poster presentation from the 9th Asia Pacific Symposium on Cochlear Implant and Related Sciences (2015).

이 논문은 장성진(2015)의 제9회 APSCI의 포스터 발표를 수정ㆍ보완하여 작성한 것임.

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