von ilberg et al . ( 1999 ) showed that it is possible to combine the electrical stimulation of a cochlear implant ( ci ) device with the acoustic stimulation of a hearing aid ( ha ) .
initially , this technique was used for patients with pure - tone thresholds of more than 60 db in the low frequencies , but it is currently possible for partially deaf patients with normal low - frequency hearing ( lfh ) to receive implants .
patients with residual hearing benefit considerably from cis alone compared with conventional has ( cullen et al .
the advantages of hybrid hearing compared with ci only have been demonstrated by von ilberg et al .
2006 , 2007 ) and hearing in complex listening situations ( gifford et al . 2013 ) seems to improve to a greater extent with hybrid hearing than with conventional ci . to date , only a few studies have investigated the quality of life and subjective ratings from hybrid hearing patients ( lenarz et al .
this procedure minimizes the trauma to the low frequency region in the apical portion the cochlea .
2007 ) , whereas other studies have reported stable hearing in the operated ear ( skarzynski et al . 2007 ; lenarz et al . 2009 ) .
nevertheless , the follow - up periods after surgery of these studies have generally been short .
the first category includes those with natural lfh who are not supposed to need amplification .
the second category includes people with lfh requiring ha amplification . both categories of people will , if their lfh is preserved , use ci hearing in the middle and high frequencies , which is called cut off frequency ci ( the stimulation is in the range of approximately 5008500 hz ) .
the devices used by these patients will be switched to include lfh and are called conventional cis or full frequency cis ( 1258500 hz ) .
after surgery , depending on the extent of surgery - induced hearing loss , the patients who are intended for hybrid hearing can be divided into the following three groups : a natural lfh with cut off frequency ci group , a ha - amplified lfh with cut off frequency ci group , and a full frequency conventional ci group . only the two first groups are hybrid - hearing patients .
it can be assumed that hybrid - hearing patients with natural lfh have better quality hearing than hybrid - hearing patients with ha - amplified lfh .
2012 ) called the first group electrical complement patients and the second group electro - acoustic stimulation patients .
the aims of this study were as follows : evaluate patient satisfaction among patients intended for hybrid hearing and the relationship of patient satisfaction with hybrid hearing ; relate hearing results in quiet and noisy conditions to subjective experiences and residual hearing ; evaluate whether ongoing deterioration of residual hearing occurred in the hybrid - hearing patients .
the study group consisted of 19 patients who were intended for hybrid hearing ( table 1 ) .
the ages at implantation ranged from 10 to 82 years and the study group consisted of 10 female and nine male patients .
age , sex , age of hearing loss , surgery ear , date of activation , mode of fitting , and usage of contralateral hearing aid from september 2008 to november 2011 , the first 24 consecutive , partially deaf patients intended for hybrid hearing underwent hearing preservation surgery in our department .
the preoperative candidacy criteria were an unaided pure - tone threshold 65 db hl at frequencies 500 hz and > 80 db hl at frequencies 2000 hz in the ear that was intended for surgery , nearly symmetrical hearing in the contralateral ear ( i.e. , the better ear ) , and aided monosyllabic word scores below 60% in each ear . in january 2013 , after all patients had used their device for at least 1 year , the patients were asked to participate in the study .
the study was approved by the regional ethical review board in uppsala ( 2012/473 ) .
the pure - tone audiograms of five of these patients have earlier been presented by erixon et al .
the patient questionnaire survey consisted of the following three parts : the international outcome inventory for hearing aids - swedish ( ioi - ha ) , which was translated into swedish in 2005 and provided by the international collegium of rehabilitative audiology .
the ioi - ha is a questionnaire that targets seven different domains via questions about the following seven topics : ( 1 ) ha use , ( 2 ) ha benefit , ( 3 ) residual activity limitations , ( 4 ) satisfaction , ( 5 ) residual participation restriction , ( 6 ) effect on others , and ( 7 ) quality of life .
factor 1 is the sum of items 1 , 2 , 4 , and 7 and represents ci satisfaction , and factor 2 is the sum of items 3 , 5 , and 6 and represents participation restriction ( kramer et al .
the questionnaire has been validated and was initially developed for the assessment of ha outcomes ( cox et al . 2000 , 2003 ) .
this instrument consists of two parts , and we used the part that involved a visual analog scale with endpoints that are labeled 
( 100 points ) and  worst imaginable health state  ( 0 points ) .
this survey was added to scrutinize residual hearing and increase the relevance of the results across different listening situations , such as listening in noisy condition and listening to music .
interested readers can access the nine - question survey in the appendix , supplemental digital content ( http://links.lww.com/eandh/a188 ) .
speech discrimination tests involving phonemically balanced monosyllabic words ( ms ) were performed with and without the has uni- and bilaterally at a comfortable level ( 6585 db sound pressure level ; svensk talaudiometri , c - a tegnr ab : 1998 ) .
the hearing in noise test ( hint ) , a speech recognition test in which everyday sentences are presented with noise , was performed for patients with sufficient hearing ( hllgren et al .
, we evaluated the pure - tone audiograms and best - aided ms and hint scores .
a round window approach was used , and the electrode was inserted slowly in steps that were interrupted by instillations of corticosteroids into the middle ear ( kenacort - t or triamcinolone solution , 40  mg / ml ) . a 24-mm long flexible electrode ( med - el flexeas )
was used in all cases with the exception of one patient who received a custom - made electrode ( 20  mm ) from med - el .
one month after surgery , a postoperative audiogram was taken , and the patients were fitted with ci processors ( opus 2 ) , and if needed , most of the patients were fitted with an ipsilateral ha at the same time ( duet 2 ) .
the patients visited our clinic on 4 days during the first 2 weeks for adjustment and training and then visited at 5 weeks and 3 , 6 , and 12 months after the fittings .
group means and alterations in pure - tone thresholds , ms , hint , and patient satisfaction scores were assessed .
the parameters were plotted , and the correlations were evaluated using excel ( microsoft ) .
the levels of significance ( i.e. , p values ) were calculated using wilcoxon s matched pairs signed rank test .
speech discrimination tests involving phonemically balanced monosyllabic words ( ms ) were performed with and without the has uni- and bilaterally at a comfortable level ( 6585 db sound pressure level ; svensk talaudiometri , c - a tegnr ab : 1998 ) . the hearing in noise test ( hint ) , a speech recognition test in which everyday sentences are presented with noise , was performed for patients with sufficient hearing ( hllgren et al .
, we evaluated the pure - tone audiograms and best - aided ms and hint scores .
a round window approach was used , and the electrode was inserted slowly in steps that were interrupted by instillations of corticosteroids into the middle ear ( kenacort - t or triamcinolone solution , 40  mg / ml ) . a 24-mm long flexible electrode ( med - el flexeas )
was used in all cases with the exception of one patient who received a custom - made electrode ( 20  mm ) from med - el .
one month after surgery , a postoperative audiogram was taken , and the patients were fitted with ci processors ( opus 2 ) , and if needed , most of the patients were fitted with an ipsilateral ha at the same time ( duet 2 ) .
the patients visited our clinic on 4 days during the first 2 weeks for adjustment and training and then visited at 5 weeks and 3 , 6 , and 12 months after the fittings .
group means and alterations in pure - tone thresholds , ms , hint , and patient satisfaction scores were assessed .
the parameters were plotted , and the correlations were evaluated using excel ( microsoft ) .
the levels of significance ( i.e. , p values ) were calculated using wilcoxon s matched pairs signed rank test .
before surgery , seven patients were intended to use unamplified lfh and a ci , and 12 patients were intended to use an ipsilateral ha and a ci . at the time of the patient survey , six patients were using unamplified lfh and a ci .
nine patients were using amplified lfh and a ci , and four patients were using a conventional full - frequency ci ( table 1 ) .
there were no surgical complications and no persistent increases in tinnitus or dizziness ; however , one patient suffered a persistent loss of chorda tympani function .
the mean ioi - ha score was 29 out of the possible 35 ( sd 3.4 , range 2235 ) .
all items are presented in table 4 separately for the hybrid hearing and nonhybrid hearing groups .
low - frequency hearing losses in the operated and contralateral ears after surgery ( 125 , 250 , and 500 hz ) patient satisfaction , experience , and speech discrimination separately for the patients with natural low - frequency hearing , the patients with hearing aids in the low frequencies and the patients with a conventional ci the groups exhibited nearly identical results on all questions with the exception of question number 5 ( residual activity limitations ) for which the nonhybrid patients indicated greater limitations .
the eq-5d visual analog scale was not completed by two patients ( table 3 ) .
the mean value across the 17 responders was 78 ( sd = 18.9 , range : 27100 ) .
the group with an ipsilateral ha scored 79 ( sd = 20.2 ) , and the nonhybrid group scored 67 ( sd = 21.2 ) .
the difference between the hybrid and nonhybrid patients was not statistically significant ( p = 0.51 ) . according to the nine - question survey , 18 patients were  very satisfied  with their ci , and
all of the patients responded that they would recommend a ci to a person in a situation similar to their own .
one patient used the ci for 4 to 8  hr per day , and one patient used the ci for 1 to 4  hr per day .
table 3 illustrates the results of the hearing in silence , hearing in noisy conditions , and hearing music tests .
. comparison of the patients with useful lfh and the full - frequency stimulation group revealed a trend toward higher scores in the former group .
regarding hearing in noisy conditions , the hybrid - hearing patients scored 3.3 ( sd = 0.9 ) compared with 2.5 ( sd = 1.0 ) for the full - frequency stimulation group .
a similar difference was found in the hearing in silence test ( 4 [ sd = 0 ] compared with 3.5 [ sd = 0.6 ] , respectively ) .
there were no differences in general satisfaction , time of use , contralateral ha use , or expected hearing .
eleven of the 15 hybrid - hearing patients claimed that music  sounded good or very good .
 all the nonhybrid patients and four of the hybrid patients did not appreciate music .
two of four patients who used the full - frequency stimulation claimed that they experienced no benefit from their residual hearing .
one patient did not respond , and one patient with a 50 db lf pta claimed a benefit .
one child stated that  a fog lifted from her ears and everything went clear  when she heard the high frequencies for the first time in her life .
all patients exhibited hearing levels within the limits of the audiometer ( 120 db ) within the range of 125500 hz .
we calculated the lf ptas at frequencies of 125 , 250 , and 500 hz .
preoperatively , the mean lf ptas were 31 db hl ( sd = 17 , min = -5 , max = 67 ) in the ears that underwent surgery and 30 db hl ( sd = 16 , min = 0 , max = 63 ) in the contralateral ears .
the lf ptas of each patient before surgery and at the follow - up are presented in figure 1 .
the mean changes of residual hearing at different frequencies after surgery are shown in figure 2 .
there was significant ( p < 0.05 ) hearing loss in the operated ears 1 month after the surgeries .
the contralateral ears displayed no significant loss during the first year but did exhibit a significant loss between the first and second year . international outcome inventory for hearing aids
results the low - frequency pure - tone averages ( 125 , 250 , and 500 hz ) in decibels are presented for each patient before the operation , 1 month postoperatively and 1 and 2 years after fitting .
the mean changes in residual hearing for each frequency 1 month after surgery , 1 and 2 years after fitting , and after 3 years for eight patients .
eight of the patients attended a 3-year follow - up visit . among these patients ,
the mean lf pta loss in the operated ear was -29 db ( sd = 19 , max = -8 , min = -58 ) , and the loss in the contralateral ear was -9 db ( sd = 7 , max = 2 , min = -17 ) 3 years after fitting .
two years after fitting , the mean lf pta losses across these eight patients were -21 db ( sd = 17 , max = 3 , min = -50 ) in the operated ear and -7 db ( sd = 5 , max = 2 , min = -13 ) in the contralateral ear . among these eight patients , there was a significant loss in the operated ear during the 3rd year after surgery .
a similar deterioration in hearing did not occur in the contralateral ear . in two children
lfh was normal ( < 20 db ) up to 500 hz in one child and up to 750 hz in the other child .
after 2 years , the lf pta losses in two children were 7 and 22 db .
the child who experienced the 22 db loss also experienced a deterioration of 8 db in her contralateral ear . before surgery , the patients displayed performances of 20% ms recognition ( sd = 19 , max = 58 , min = 0 ) in the ear intended for surgery and 35% ( sd = 17 , max = 64 , min = 6 ) in the other ear in their best - aided conditions .
the mss were presented at a mean sound intensity of 72 db ( sd = 5 , max = 85 , min = 65 ) .
binaurally , the patients displayed 39% ms recognition ( sd = 17 , max = 70 , min = 10 ) at the mean sound intensity of 70 db ( sd = 4 , max = 80 , min = 65 ) . at 1-year follow - up ( data from two patients were missing ) , the patients displayed 52% ms recognition performance ( sd = 19 , max = 80 , min = 12 ) in the implanted ear in their best - aided condition .
the mss were presented at a mean sound intensity of 69 db ( sd = 3 , max = 75 , min = 65 ) .
binaurally , the patients ( data from three patients were missing ) displayed 63% ms recognition performance ( sd = 16 , max = 88 , min = 34 ) at a mean sound intensity of 69 db ( sd = 3 , max = 75 , min = 65 ) .
at the 2-year follow - up ( the data from one patient was missing ) , the patients displayed 45% ms recognition performance ( sd = 27 , max = 82 , min = 0 ) in the operated ear .
the mss were presented at a mean sound intensity of 68 db ( sd = 4.2 , max = 80 , min = 65 ) .
binaurally , the patients ( all patients ) exhibited 58% ms recognition ( sd = 17 , max = 90 , min = 22 ) at the mean sound intensity of 67 db ( sd = 3 , max = 75 , min = 65 ) .
nine patients were unable to perform the hint test before surgery due to poor hearing .
ten patients presented with a mean hint result of a 15 db signal to noise ratio ( snr ) in the binaural best - aided listening situation ( sd = 4 , max = 10 , min = 22 ) . in the ear that was intended for surgery ( nine patients ) , the snr was 16 db ( sd = 6 , max = 21 , min = 3 ) . at 1-year follow - up ( 18 patients ) , the mean binaural snr was 4.2 db ( sd = 4 , max = -1.6 , min = 10.6 ) , and in the operated ear ( 14 patients ) , the snr was 6.0 db ( sd = 5 , max = 17 , min = 0 ) .
the individual results after 1 year are illustrated in table 3 . in the nine patients with preoperative hint scores , the binaural gain in the snr was 11 db after 1 year .
a mean gain of 11 db was observed in the operated ears of the five patients as measured monaurally .
after 2 years , hint scores were assessed bilaterally in all of the patients , and the snr was 4.6 db ( sd = 3.4 , max = -1.7 , min 12.= 5 ) . for the operated ear alone ( 14 patients ) ,
the snr was 5.8 db ( sd = 3 , max = 11.5 , min = 0 ) .
the two children did quite well in the silent condition before surgery ( one performed an easier test designed for children ) .
after surgery , the children s hearing was approximately the same as it was before surgery . on the hint test , the children exhibited a gain of 1112 db and presented with snrs of -1.6 and 0.1 db after 1 year .
there were tendencies for the hybrid - hearing patients to experience better hearing and be more satisfied , but these trends were not statistically significant for any of the questions .
both the patients who scored the best and worst on the ms and hint were found in the hybrid - hearing group .
the patients perceptions of improved hearing in silence and noise were not correlated with the postoperative ms or hint scores or with the ms or hint gains .
all patients with a snr ratio below 1 db in the hint experienced better or much better hearing in noisy environments after implantation .
the mean ioi - ha score was 29 out of the possible 35 ( sd 3.4 , range 2235 ) .
all items are presented in table 4 separately for the hybrid hearing and nonhybrid hearing groups .
low - frequency hearing losses in the operated and contralateral ears after surgery ( 125 , 250 , and 500 hz ) patient satisfaction , experience , and speech discrimination separately for the patients with natural low - frequency hearing , the patients with hearing aids in the low frequencies and the patients with a conventional ci the groups exhibited nearly identical results on all questions with the exception of question number 5 ( residual activity limitations ) for which the nonhybrid patients indicated greater limitations .
the eq-5d visual analog scale was not completed by two patients ( table 3 ) .
the mean value across the 17 responders was 78 ( sd = 18.9 , range : 27100 ) .
the group with an ipsilateral ha scored 79 ( sd = 20.2 ) , and the nonhybrid group scored 67 ( sd = 21.2 ) .
the difference between the hybrid and nonhybrid patients was not statistically significant ( p = 0.51 ) . according to the nine - question survey , 18 patients were  very satisfied  with their ci , and one patient was  satisfied . 
all of the patients responded that they would recommend a ci to a person in a situation similar to their own .
one patient used the ci for 4 to 8  hr per day , and one patient used the ci for 1 to 4  hr per day .
table 3 illustrates the results of the hearing in silence , hearing in noisy conditions , and hearing music tests .
. comparison of the patients with useful lfh and the full - frequency stimulation group revealed a trend toward higher scores in the former group . regarding hearing in noisy conditions
, the hybrid - hearing patients scored 3.3 ( sd = 0.9 ) compared with 2.5 ( sd = 1.0 ) for the full - frequency stimulation group .
a similar difference was found in the hearing in silence test ( 4 [ sd = 0 ] compared with 3.5 [ sd = 0.6 ] , respectively ) . there were no differences in general satisfaction , time of use ,
eleven of the 15 hybrid - hearing patients claimed that music  sounded good or very good .
 all the nonhybrid patients and four of the hybrid patients did not appreciate music .
two of four patients who used the full - frequency stimulation claimed that they experienced no benefit from their residual hearing .
one patient did not respond , and one patient with a 50 db lf pta claimed a benefit .
one child stated that  a fog lifted from her ears and everything went clear  when she heard the high frequencies for the first time in her life .
all patients exhibited hearing levels within the limits of the audiometer ( 120 db ) within the range of 125500 hz .
we calculated the lf ptas at frequencies of 125 , 250 , and 500 hz .
preoperatively , the mean lf ptas were 31 db hl ( sd = 17 , min = -5 , max = 67 ) in the ears that underwent surgery and 30 db hl ( sd = 16 , min = 0 , max = 63 ) in the contralateral ears .
the lf ptas of each patient before surgery and at the follow - up are presented in figure 1 .
the mean changes of residual hearing at different frequencies after surgery are shown in figure 2 .
there was significant ( p < 0.05 ) hearing loss in the operated ears 1 month after the surgeries .
the contralateral ears displayed no significant loss during the first year but did exhibit a significant loss between the first and second year .
international outcome inventory for hearing aids results the low - frequency pure - tone averages ( 125 , 250 , and 500 hz ) in decibels are presented for each patient before the operation , 1 month postoperatively and 1 and 2 years after fitting .
the mean changes in residual hearing for each frequency 1 month after surgery , 1 and 2 years after fitting , and after 3 years for eight patients .
eight of the patients attended a 3-year follow - up visit . among these patients ,
the mean lf pta loss in the operated ear was -29 db ( sd = 19 , max = -8 , min = -58 ) , and the loss in the contralateral ear was -9 db ( sd = 7 , max = 2 , min = -17 ) 3 years after fitting .
two years after fitting , the mean lf pta losses across these eight patients were -21 db ( sd = 17 , max = 3 , min = -50 ) in the operated ear and -7 db ( sd = 5 , max = 2 , min = -13 ) in the contralateral ear . among these eight patients , there was a significant loss in the operated ear during the 3rd year after surgery . a similar deterioration in hearing did not occur in the contralateral ear . in two children
lfh was normal ( < 20 db ) up to 500 hz in one child and up to 750 hz in the other child .
after 2 years , the lf pta losses in two children were 7 and 22 db .
the child who experienced the 22 db loss also experienced a deterioration of 8 db in her contralateral ear .
before surgery , the patients displayed performances of 20% ms recognition ( sd = 19 , max = 58 , min = 0 ) in the ear intended for surgery and 35% ( sd = 17 , max = 64 , min = 6 ) in the other ear in their best - aided conditions .
the mss were presented at a mean sound intensity of 72 db ( sd = 5 , max = 85 , min = 65 ) .
binaurally , the patients displayed 39% ms recognition ( sd = 17 , max = 70 , min = 10 ) at the mean sound intensity of 70 db ( sd = 4 , max = 80 , min = 65 ) . at 1-year follow - up ( data from two patients were missing ) , the patients displayed 52% ms recognition performance ( sd = 19 , max = 80 , min = 12 ) in the implanted ear in their best - aided condition .
the mss were presented at a mean sound intensity of 69 db ( sd = 3 , max = 75 , min = 65 ) .
binaurally , the patients ( data from three patients were missing ) displayed 63% ms recognition performance ( sd = 16 , max = 88 , min = 34 ) at a mean sound intensity of 69 db ( sd = 3 , max = 75 , min = 65 ) .
at the 2-year follow - up ( the data from one patient was missing ) , the patients displayed 45% ms recognition performance ( sd = 27 , max = 82 , min = 0 ) in the operated ear .
the mss were presented at a mean sound intensity of 68 db ( sd = 4.2 , max = 80 , min = 65 ) .
binaurally , the patients ( all patients ) exhibited 58% ms recognition ( sd = 17 , max = 90 , min = 22 ) at the mean sound intensity of 67 db ( sd = 3 , max = 75 , min = 65 ) .
nine patients were unable to perform the hint test before surgery due to poor hearing .
ten patients presented with a mean hint result of a 15 db signal to noise ratio ( snr ) in the binaural best - aided listening situation ( sd = 4 , max = 10 , min = 22 ) . in the ear that was intended for surgery ( nine patients ) , the snr was 16 db ( sd = 6 , max = 21 , min = 3 ) . at 1-year follow - up ( 18 patients ) , the mean binaural snr was 4.2 db ( sd = 4 , max = -1.6 , min = 10.6 ) , and in the operated ear ( 14 patients ) , the snr was 6.0 db ( sd = 5 , max = 17 , min = 0 ) .
the individual results after 1 year are illustrated in table 3 . in the nine patients with preoperative hint scores , the binaural gain in the snr was 11 db after 1 year .
a mean gain of 11 db was observed in the operated ears of the five patients as measured monaurally .
after 2 years , hint scores were assessed bilaterally in all of the patients , and the snr was 4.6 db ( sd = 3.4 , max = -1.7 , min 12.= 5 ) . for the operated ear alone ( 14 patients ) ,
the snr was 5.8 db ( sd = 3 , max = 11.5 , min = 0 ) .
the two children did quite well in the silent condition before surgery ( one performed an easier test designed for children ) .
after surgery , the children s hearing was approximately the same as it was before surgery . on the hint test , the children exhibited a gain of 1112 db and presented with snrs of -1.6 and 0.1 db after 1 year .
there were tendencies for the hybrid - hearing patients to experience better hearing and be more satisfied , but these trends were not statistically significant for any of the questions .
both the patients who scored the best and worst on the ms and hint were found in the hybrid - hearing group .
the patients perceptions of improved hearing in silence and noise were not correlated with the postoperative ms or hint scores or with the ms or hint gains .
all patients with a snr ratio below 1 db in the hint experienced better or much better hearing in noisy environments after implantation .
in this study , we evaluate patient satisfaction among patients intended for hybrid hearing and relate hearing results in quiet and noisy conditions to subjective experiences and residual hearing .
results showed that electric stimulation provides a major contribution to speech comprehension in partially deaf patients and that all of the patients were satisfied with their cis regardless of the variation in the extent of hearing preservation .
all of our patients reported that they would recommend a ci to a person in a situation similar to theirs , and this is a major sign of patient satisfaction .
the overall benefits in high - frequency hearing seemed to outweigh the possible benefits of preserved lfh . because only four patients lost the possibility of hybrid hearing , the cohort was too limited to assess the possible advantages of hybrid hearing .
a control group lacking usable lfh in the ipsilateral ear could not be obtained because the majority of conventional ci patients have profound bilateral hearing loss across all frequencies .
within - subject comparisons were not possible because earplugs and ear defenders are estimated to mask only approximately 30 db in the lower frequencies , which is insufficient when lfh is normal .
plugging of the operated ear was performed in a few patients to evaluate lfh when considering full - frequency ci stimulation or ha .
( 2013 ) performed within - subject comparisons and showed that hybrid hearing is superior to nonhybrid hearing . the patient satisfaction survey employed by these authors only compared hybrid hearing with preoperative ha hearing .
because it can be assumed that patients with natural unamplified lfh might hear better than those with ha - amplified lfh , we found it useful to separate the results based on three ci groups .
a disadvantage is that patients with similar lfh might choose different fitting strategies , which may include ipsilateral has .
thus , we compared the levels of satisfaction related to the actual lfh and those related to the different groups .
( 2013 ) analyzed a fairly small patient sample and also found no differences in patient satisfaction between the hybrid and nonhybrid patients .
the ioi - ha scores of our patients were nearly identical to those reported by redfors et al .
these authors also claimed that the patients with mixed hearing loss scored better than did the patients with only sensorineural hearing loss using a ha . our results indicate that music perception was better among the hybrid - hearing patients than the nonhybrid patients .
contralateral hearing might also have contributed to the musical experiences because the patients with minimal lfh predominantly had similar situations in their contralateral ears .
some of the patients had normal hearing since birth , and others had limited memories of high - frequency hearing .
some of the patients were very satisfied by relatively small improvements , particularly if they had experienced a long - lasting period of profound hearing loss with limited hearing experiences .
there are several methods to for examining hearing loss related to hearing preservation surgeries ( incerti et al .
because all of our patients exhibited ski - slope shaped audiograms and because all of our patients had measurable hearing in the 125500 hz range postoperatively , we found our selected method to be practical and easy to use every day in the clinic .
( 2013 ) characterized hearing preservation either as complete ( 10 db ) or partial ( 30 db ) . in this study , among the 66 patients , 43% exhibited complete preservation , and 74% exhibited partial preservation after 1 year .
the rest of the patients 26% have no preserved hearing according to the criteria ) . in this investigation
, 32% of our patients exhibited complete preservation , and 95% exhibited partial preservation after 1 month . at 1 year , the corresponding values were 21% and 89% , respectively ; at 2 years , the values were 26% and 63% , respectively .
these results indicate that the number of patients with completely preserved hearing was less in our study than in the study by lenarz et al . , but the number of patients with partially preserved hearing was higher in our study .
a loss of 30 db could be the difference between using and not using an acoustic complement . despite the ubiquitous hearing preservation after round window surgery , deteriorations in the lfh of the operated ears were observed during the 1st years .
the finding that the loss was more advanced in the operated ear suggests that this loss might have been induced by the electrode array .
the explanation for the less severe hearing loss that was observed in the nonoperated ears might be related to the etiologies of the hearing impairments of our patients ( usami et al .
2012 ) . we did not find a way to predict hearing deterioration immediately after surgery or thereafter
. a better understanding of the etiology of hearing loss might contribute to such predictions in the future .
because the loss of residual hearing could not be predicted , the progression of lfh loss should always be considered and discussed in patient consultations , but this should not be considered a contraindication for implantation because patients will benefit from cis .
if the lf pta is 50 db before surgery , the patients will likely not use ipsilateral has .
the patients who switched from the hybrid hearing strategy to the full frequency program due to greater lfh loss did not complain , likely because they gained full - frequency ci hearing and maintained lfh in the contralateral ear .
these patients were pleased with the easier handling of the processor , which did not obstruct the ear canal .
the patients with initial unaided lfh , who deteriorated after fitting abandoned the hybrid - hearing strategy and used full - frequency cis .
one patient preferred the full - frequency stimulation despite having normal lfh , and another patient chose to use a full - frequency ci stimulation and a ha during 2 years .
these results indicate the remarkable potential of the  listening  brain and demonstrate the complexity of identifying the best - aided condition .
because our patients had natural lfh in their contralateral ears , they likely suffered less from the ipsilateral lfh loss .
further studies are necessary before standard indications for bilateral hybrid hearing implantations can be established .
one year after surgery , the patients displayed a mean performance of 52% in the ms test in the operated ear .
the hint results after 1 year are in accordance with those of gifford et al .
after 2 years , slight reductions in the ms and hint scores were observed . when asked , the majority of the patients responded that they experienced stable or improved hearing . in many patients ,
factors , such as preoperative hearing ability , individual expectations , and environmental needs might explain these inconsistencies .
these findings illustrate the value of assessing both patient satisfaction scores and audiological to understand the actual hearing situation .
the two children included in this report were described separately because they seemed to exhibit the possibility for successful ci rehabilitation despite profound high - frequency deafness since childhood .
such children may benefit from receiving high - frequency cis early and experiencing improved hearing at a critical time of their lives .
because both of the children in our study had normal preoperative lfh , they might benefit from hybrid hearing for many years despite the ongoing deteriorations of their residual hearing .
such benefits of hybrid hearing might be found to be important for the optimal education and social development of these children .
all of the patients were satisfied with their cis regardless of the variation in the extent of hearing preservation .
the preservation of hearing constitutes an additional benefit that might improve hearing in noisy situations and music perception .
we observed ongoing deterioration of the residual hearing of the operated ear that surpassed the deterioration of the contralateral ear .
based on our findings , we propose that most people with partial deafness should be offered hybrid hearing .
evaluations of patient satisfaction should be used with conventional hearing tests to increase our knowledge of ci hearing .
 objectives : to measure patient satisfaction and correlate to hearing results in partially deaf patients , after hearing preservation cochlear implant surgery with hybrid hearing strategy , and to evaluate the stability of residual low - frequency hearing ( lfh ) over time.design:a patient satisfaction survey and a retrospective , 2-year follow - up journal study . 
 nineteen partially deaf patients intended for hybrid hearing responded to a questionnaire when they had used their cochlear implants for at least a year . 
 the questionnaire consisted of the international outcome inventory for hearing aids , euroqol group visual analogue scale and nine questions about hybrid hearing . 
 pure - tone audiometry , monosyllables , and hearing in noise test results from the patients medical records were evaluated and compared with the results from the patient satisfaction survey.results:all of the patients were satisfied with their cis . 
 the mean international outcome inventory for hearing aids score was 29 . 
 the cis provided a major contribution to the speech comprehension of these partially deaf patients . 
 two years after surgery , the patients mean binaural score on tests of monosyllables was 58% , and the mean signal to noise ratio was 4.6 db . 
 we observed ongoing deteriorations in the residual hearing of the operated ears that surpassed the deteriorations observed in the contralateral ears . 
 one month after surgery , the lfh loss ( 125500 hz ) was 17 db , and after 2 years , this loss was 24 db compared with 5 db in the nonoperated ear . 
 there were no significant correlations between preserved lfh and patient satisfaction or speech perception results.conclusions:electric stimulation provided a major contribution to speech comprehension of partially deaf patients . 
 the gain reached in speech understanding widely exceeded the downside in losing some residual hearing . 
 all the patients showed a high degree of satisfaction with their cis regardless of varying hearing preservation . 