Music Is More Enjoyable With Two Ears, Even If One of Them Receives a Degraded Signal Provided By a Cochlear Implant.

OBJECTIVES: Cochlear implants (CIs) restore speech perception in quiet but they also eliminate or distort many acoustic cues that are important for music enjoyment. Unfortunately, quantifying music enjoyment by CI users has been difficult because comparisons must rely on their recollection of music before they lost their hearing. Here, we aimed to assess music enjoyment in CI users using a readily interpretable reference based on acoustic hearing. The comparison was done by testing "single-sided deafness" (SSD) patients who have normal hearing (NH) in one ear and a CI in the other ear. The study also aimed to assess binaural musical enjoyment, with the reference being the experience of hearing with a single NH ear. Three experiments assessed the effect of adding different kinds of input to the second ear: electrical, vocoded, or unmodified. DESIGN: In experiment 1, music enjoyment in SSD-CI users was investigated using a modified version of the MUSHRA (MUltiple Stimuli with Hidden Reference and Anchor) method. Listeners rated their enjoyment of song segments on a scale of 0 to 200, where 100 represented the enjoyment obtained from a song segment presented to the NH ear, 0 represented a highly degraded version of the same song segment presented to the same ear, and 200 represented enjoyment subjectively rated as twice as good as the 100 reference. Stimuli consisted of acoustic only, electric only, acoustic and electric, as well as other conditions with low pass filtered acoustic stimuli. Acoustic stimulation was provided by headphone to the NH ear and electric stimulation was provided by direct audio input to the subject's speech processor. In experiment 2, the task was repeated using NH listeners who received vocoded stimuli instead of electric stimuli. Experiment 3 tested the effect of adding the same unmodified song segment to the second ear, also in NH listeners. RESULTS: Music presented through the CI only was very unpleasant, with an average rating of 20. Surprisingly, the combination of the unpleasant CI signal in one ear with acoustic stimulation in the other ear was rated more enjoyable (mean = 123) than acoustic processing alone. Presentation of the same monaural musical signal to both ears in NH listeners resulted with even greater enhancement of the experience compared with presentation to a single ear (mean = 159). Repeating the experiment using a vocoder to one ear of NH listeners resulted in interference rather than enhancement. CONCLUSIONS: Music enjoyment from electric stimulation is extremely poor relative to a readily interpretable NH baseline for CI-SSD listeners. However, the combination of this unenjoyable signal presented through a CI and an unmodified acoustic signal presented to a NH (or near-NH) contralateral ear results in enhanced music enjoyment with respect to the acoustic signal alone. Remarkably, this two-ear enhancement experienced by CI-SSD listeners represents a substantial fraction of the two-ear enhancement seen in NH listeners. This unexpected benefit of electroacoustic auditory stimulation will have to be considered in theoretical accounts of music enjoyment and may facilitate the quest to enhance music enjoyment in CI users.

The P300 auditory event-related potential as a method to assess the benefit of contralateral hearing aid use in bimodal listeners: a proof-of-concept.

Objective: Bimodal listeners vary in the amount of benefit they receive from wearing the contralateral hearing aid. This may partially depend on the listener's auditory processing capacities. The current study explores whether the P300 event-related potential can provide insight into the mechanisms underlying the benefits of wearing a contralateral hearing aid.Design: P300s were recorded using an oddball paradigm with 500 and 250 Hz tone-bursts as standard and deviant stimuli, respectively. Subjects counted the number of deviants - a measure of performance. N2b latencies, P300 latencies, N2b-P300 amplitudes, and performance were assessed during CI-only and bimodal listening.Study sample: Five bimodal listeners.Results: P300s were present in four subjects. Amplitudes were larger during bimodal listening (bimodal: 22.3 ± 4.83 µV, CI-only: 13.1 ± 3.86 µV). Both N2b and P300 latencies were shorter during bimodal (N2b: 265 ± 20.0 ms, P300: 551 ± 129.4 ms) than CI-only listening (N2b: 326 ± 42.2 ms, P300: 402 ± 38.4 ms). While performance often reached ceiling level, the difference between the standard and deviant was generally more salient during bimodal listening.Conclusions: This study provides a proof-of-concept, suggesting that P300s may provide insight into benefits that are not always measurable with behavioural tasks.

Age-Related Changes in Binaural Interaction at Brainstem Level.

OBJECTIVES: Age-related hearing loss hampers the ability to understand speech in adverse listening conditions. This is attributed to a complex interaction of changes in the peripheral and central auditory system. One aspect that may deteriorate across the lifespan is binaural interaction. The present study investigates binaural interaction at the level of the auditory brainstem. It is hypothesized that brainstem binaural interaction deteriorates with advancing age. DESIGN: Forty-two subjects of various age participated in the study. Auditory brainstem responses (ABRs) were recorded using clicks and 500 Hz tone-bursts. ABRs were elicited by monaural right, monaural left, and binaural stimulation. Binaural interaction was investigated in two ways. First, grand averages of the binaural interaction component were computed for each age group. Second, wave V characteristics of the binaural ABR were compared with those of the summed left and right ABRs. RESULTS: Binaural interaction in the click ABR was demonstrated by shorter latencies and smaller amplitudes in the binaural compared with the summed monaural responses. For 500 Hz tone-burst ABR, no latency differences were found. However, amplitudes were significantly smaller in the binaural than summed monaural condition. An age-effect was found for 500 Hz tone-burst, but not for click ABR. CONCLUSIONS: Brainstem binaural interaction seems to decline with age. Interestingly, these changes seem to be stimulus-dependent.

Qualities of Single Electrode Stimulation as a Function of Rate and Place of Stimulation with a Cochlear Implant.

OBJECTIVES: Although it has been shown previously that changes in temporal coding produce changes in pitch in all cochlear regions, research has suggested that temporal coding might be best encoded in relatively apical locations. The authors hypothesized that although temporal coding may provide useable information at any cochlear location, low rates of stimulation might provide better sound quality in apical regions that are more likely to encode temporal information in the normal ear. In the present study, sound qualities of single electrode pulse trains were scaled to provide insight into the combined effects of cochlear location and stimulation rate on sound quality. DESIGN: Ten long-term users of MED-EL cochlear implants with 31-mm electrode arrays (Standard or FLEX) were asked to scale the sound quality of single electrode pulse trains in terms of how "Clean," "Noisy," "High," and "Annoying" they sounded. Pulse trains were presented on most electrodes between 1 and 12 representing the entire range of the long electrode array at stimulation rates of 100, 150, 200, 400, or 1500 pulses per second. RESULTS: Although high rates of stimulation are scaled as having a Clean sound quality across the entire array, only the most apical electrodes (typically 1 through 3) were considered Clean at low rates. Low rates on electrodes 6 through 12 were not rated as Clean, whereas the low-rate quality of electrodes 4 and 5 were typically in between. Scaling of Noisy responses provided an approximately inverse pattern as Clean responses. High responses show the trade-off between rate and place of stimulation on pitch. Because High responses did not correlate with Clean responses, subjects were not rating sound quality based on pitch. CONCLUSIONS: If explicit temporal coding is to be provided in a cochlear implant, it is likely to sound better when provided apically. In addition, the finding that low rates sound clean only at apical places of stimulation is consistent with previous findings that a change in rate of stimulation corresponds to an equivalent change in perceived pitch at apical locations. Collectively, the data strongly suggest that temporal coding with a cochlear implant is optimally provided by electrodes placed well into the second cochlear turn.

Contraceptive use in Flanders (Belgium): A comparison between a general population sample and a Turkish ethnic minority sample.

OBJECTIVES: To identify contraceptive profiles, and factors affecting these, among women of childbearing age, living in Flanders. METHODS: The prevalence of knowledge and use of the emergency contraceptive pill (ECP) and contraceptive use is assessed in two samples from the SEXPERT-survey 'Sexual health in Flanders': (i) a population-based sample (n = 724); and (ii) a probability sample of respondents of Turkish descent (n = 216). RESULTS: Knowledge, but not use, of the ECP is significantly lower among women from the ethnic minority sample, even after correction for income and educational background. A lower educational level is associated with less knowledge of the ECP in both samples. In the general population sample, 16% of sexually active women of childbearing age are at risk of an unplanned pregnancy, compared to 14% of their peers of Turkish origin. These rates are comparable, even after controlling for the different socio-economic status (income and educational level) in both samples. CONCLUSIONS: Contraceptive profiles of sexually active women of Turkish descent residing in Flanders are mostly similar to those of their counterparts in the general population. Further research is required to develop strategies to improve ECP-knowledge among women with lower educational achievements.

Assessment of the subjective benefit of electric acoustic stimulation with the abbreviated profile of hearing aid benefit.

CONCLUSION: This study demonstrates that electric-acoustic stimulation (EAS) significantly decreases the subjective impairment in speech perception. OBJECTIVES: To assess the subjective benefit of EAS over the first 12 months after EAS fitting using the Abbreviated Profile of Hearing Aid Benefit (APHAB). METHOD: Twenty-three EAS users, implanted with either the PULSAR(CI)(100) FLEX(EAS) provided with the DUET EAS processor or the COMBI40+ Medium provided with the TEMPO+ speech processor, were included. Electric stimulation was activated about 1 month postoperatively; ipsilateral acoustic stimulation was added 2 months thereafter. EAS benefit was measured preoperatively with only a hearing aid and postoperatively at EAS fitting and then 3, 6 and 12 months after EAS fitting using the APHAB. RESULTS: Subjects reported significant improvements in the global score with a mean decrease in impairment from 74% preoperatively to 45% after 3 months of EAS use. Furthermore, clinical relevance was demonstrated in multiple subscales between preoperative and first fitting reflecting a true benefit of EAS with a probability of 95%.

Better speech recognition in noise with the fine structure processing coding strategy.

BACKGROUND: Recently, a new speech coding strategy named 'fine structure processing' (FSP) has been launched. METHODS: 32 subjects, all users of the MED-EL PULSARCI(100) system, have been switched over from a TEMPO+ to an OPUS 2 speech processor. In 22 subjects, the FSP strategy could be implemented (FSP group), in 10 patients not (high-definition continuous interleaved sampling, HDCIS, group). Subjects were tested with the Tempo+ (CIS+) just before switch-over and after 12 months of OPUS 2 (FSP/HDCIS) use. Performance with FSP/HDCIS was tested at switch-over, and after 1, 3, 6 and 12 months. A sentence-in-noise test and a Speech Spatial and Qualities of Hearing Scale (SSQ) questionnaire were assessed at each test interval. RESULTS: In the FSP group, the speech reception threshold shows a deterioration of 3.3 dB (n.s.) at the acute switch-over interval, but a significant improvement over time (p < 0.001) with a final benefit of 6.5 dB after 12 months of FSP use. A significant improvement over time can also be seen on the spatial subscore of the SSQ questionnaire (p = 0.009). No significant differences could be seen in the HDCIS group. CONCLUSION: The results show that by enhancing fine structure coding in the lower frequencies, as implemented in the FSP coding strategy, speech perception in noise can be enhanced.

Binaural hearing after cochlear implantation in subjects with unilateral sensorineural deafness and tinnitus.

The aim of this clinical study was to assess speech recognition in noise after cochlear implantation in subjects with single-sided deafness and incapacitating tinnitus. 20 subjects complaining of severe intractable tinnitus unresponsive to treatment received a MED-EL cochlear implant (CI). 11 subjects had normal hearing (NH group) on the contralateral side, while 9 used a hearing aid (HA group). The subjects were tested in noise in two listening conditions, i.e. with their acoustic hearing only and with adding the CI to the acoustic hearing (binaural). Subjective improvement in daily life was evaluated using the Speech Spatial and Qualities Hearing Scale (SSQ). The summation effect (3.3 dB for the HA group and 0.6 dB for the NH group) is not significant in both groups. A significant squelch effect of adding the CI was seen for the HA users (3.8 dB), but not for the NH group (1.2 dB). Additionally, a significant effect of adding the CI was found for the spatial configuration where noise is presented in front and speech on the CI side for both the HA group (6.5 dB) and the NH group (1.7 dB). Results of the SSQ show a significant overall benefit of wearing the CI for both groups. The preliminary results of these 20 subjects suggest that cochlear implantation can improve hearing in people suffering from single-sided deafness combined with tinnitus.

Rhyme Awareness in Children With Normal Hearing and Children With Cochlear Implants: An Exploratory Study.

Phonological awareness is a critical component of phonological processing that predicts children's literacy outcomes. Phonological awareness skills enable children to think about the sound structure of words and facilitates decoding and the analysis of words during spelling. Past research has shown that children's vocabulary knowledge and working memory capacity are associated with their phonological awareness skills. Linguistic characteristics of words, such as phonological neighborhood density and orthography congruency have also been found to influence children's performance in phonological awareness tasks. Literacy is a difficult area for deaf and hard of hearing children, who have poor phonological awareness skills. Although cochlear implantation (CI) has been found to improve these children's speech and language outcomes, limited research has investigated phonological awareness in children with CI. Rhyme awareness is the first level of phonological awareness to develop in children with normal hearing (NH). The current study investigates whether rhyme awareness in children with NH (n = 15, median age = 5; 5, IQR = 11 ms) and a small group of children with CI (n = 6, median age = 6; 11.5, IQR = 3.75 ms) is associated with individual differences in vocabulary and working memory. Using a rhyme oddity task, well-controlled for perceptual similarity, we also explored whether children's performance was associated with linguistic characteristics of the task items (e.g., rhyme neighborhood density, orthographic congruency). Results indicate that there is an association between vocabulary and working memory and performance in a rhyme awareness task in NH children. Only working memory was correlated with rhyme awareness performance in CI children. Linguistic characteristics of the task items, on the other hand, were not found to be associated with success. Implications of the results and future directions are discussed.

Relationship Between Working Memory and Speech-in-Noise Recognition in Young and Older Adult Listeners With Age-Appropriate Hearing.

Purpose The purpose of this study was to investigate the relationship between working memory (WM) capacity and speech recognition in noise in both a group of young adults and a group of older adults. Method Thirty-three older adults with a mean age of 71.0 (range: 60.4-82.7) years and 27 young adults with a mean age of 21.7 (range: 19.1-25.0) years participated in the study. All participants had age-appropriate hearing and no history of central nervous system dysfunction. WM capacity was measured using the van den Noort version of the Reading Span Test, and recognition of sentences in the presence of a stationary speech-shaped noise was measured as the speech reception threshold for 50% correct identification by using the Leuven Intelligibility Sentence Test. Results The older adults had significantly worse WM capacity scores, t(58) = 8.266, p < .001, and significantly more difficulty understanding sentences in noise than the younger adults, t(58) = -6.068, p < .001. In the group of older adults, a correlation was found (r = -.488, n = 33, p = .004) between the results of the WM capacity test (Reading Span Test) and the results of the speech-recognition-in-noise test (Leuven Intelligibility Sentence Test), meaning that the higher the WM performance was, the better was the speech recognition in noise. This correlation cannot be found in young normal-hearing listeners. Conclusions This study shows deleterious effects of age on both WM capacity and speech recognition in noise. Interestingly, only in the group of older adults was a significant relation found between WM capacity and speech recognition in noise. The current results caution against the assumption that WM necessarily supports speech-in-noise identification independently of the age and hearing status of the listener.

The Relationship Between Linguistic Ability, Multilingualism, and Dementia.

In a recent article of the Journal of Alzheimer's Disease, Hack et al. (2019) argue that linguistic ability rather than multilingualism is a significant predictor of dementia. In their longitudinal study, they investigated 325 religious sisters who were older than 75 years of age. Self-reports were used in order to determine multilingualism. They found that speaking two or three languages did not delay the onset of dementia. However, they did find that individuals speaking four or more languages were less likely to suffer from dementia than those speaking only one language and concluded that having linguistic ability was a more significant predictor of dementia than being multilingual. However, more research is needed in order to identify the characteristics of multilingualism most salient for the risk of dementia. In this commentary, we raise several important methodological and statistical issues that are likely to have affected the findings of Hack et al.'s study. As a result, although their study makes an important contribution to the research field, drawing a conclusion at this time that linguistic ability is more a predictor of dementia than multilingualism would be premature; moreover, their preliminary results cannot be generalized to the general population.

A Systematic Review on the Possible Relationship Between Bilingualism, Cognitive Decline, and the Onset of Dementia.

A systematic review was conducted to investigate whether bilingualism has a protective effect against cognitive decline in aging and can protect against dementia. We searched the Medline, ScienceDirect, Scopus, and ERIC databases with a cut-off date of 31 March, 2019, thereby following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) protocol. Our search resulted in 34 eligible studies. Mixed results were found with respect to the protective effect of bilingualism against cognitive decline. Several studies showed a protective effect whereas other studies failed to find it. Moreover, evidence for a delay of the onset of dementia of between 4 and 5.5 years in bilingual individuals compared to monolinguals was found in several studies, but not in all. Methodological differences in the set-up of the studies seem to explain these mixed results. Lifelong bilingualism is a complex individual process, and many factors seem to influence this and need to be further investigated. This can be best achieved through large longitudinal studies with objective behavioral and neuroimaging measurements. In conclusion, although some evidence was found for a cognitive reserve-enhancing effect of lifelong bilingualism and protection against dementia, to date, no firm conclusions can be drawn.

Does the Bilingual Advantage in Cognitive Control Exist and If So, What Are Its Modulating Factors? A Systematic Review.

Recently, doubts were raised about the existence of the bilingual advantage in cognitive control. The aim of the present review was to investigate the bilingual advantage and its modulating factors. We searched the Medline, ScienceDirect, Scopus, and ERIC databases for all original data and reviewed studies on bilingualism and cognitive control, with a cut-off date of 31 October 2018, thereby following the guidelines of the preferred reporting items for systematic reviews and meta-analysis (PRISMA) protocol. The results of the 46 original studies show that indeed, the majority, 54.3%, reported beneficial effects of bilingualism on cognitive control tasks; however, 28.3% found mixed results and 17.4% found evidence against its existence. Methodological differences seem to explain these mixed results: Particularly, the varying selection of the bilingual participants, the use of nonstandardized tests, and the fact that individual differences were often neglected and that longitudinal designs were rare. Therefore, a serious risk for bias exists in both directions (i.e., in favor of and against the bilingual advantage). To conclude, we found some evidence for a bilingual advantage in cognitive control; however, if significant progress is to be made, better study designs, bigger data, and more longitudinal studies are needed.

Neural tonotopy in cochlear implants: an evaluation in unilateral cochlear implant patients with unilateral deafness and tinnitus.

In cochlear implants, the signal is filtered into different frequency bands and transmitted to electrodes along the cochlea. In this study the frequency-place function for electric hearing was investigated as a means to possibly improve speech coding by delivering information to the appropriate cochlear place. Fourteen subjects with functional hearing in the contralateral ear have been provided with a MED-EL cochlear implant in the deaf ear in order to reduce intractable tinnitus. Pitch scaling experiments were performed using single-electrode, constant-amplitude, constant-rate stimuli in the implanted ear, and acoustic sinusoids in the contralateral ear. The frequency-place function was calculated using the electrode position in the cochlea as obtained from postoperative skull radiographs. Individual frequency-place functions were compared to Greenwood's function in normal hearing. Electric stimulation elicited a low pitch in the apical region of the cochlea, and shifting the stimulating electrode towards the basal region elicited increasingly higher pitch. The frequency-place function did not show a significant shift relative to Greenwood's function. In cochlear implant patients with functional hearing in the non-implanted ear, electrical stimulation produced a frequency-place function that on average resembles Greenwood's function. These results differ from previously derived data.

Incapacitating unilateral tinnitus in single-sided deafness treated by cochlear implantation.

OBJECTIVES: Tinnitus is a well-known, difficult-to-treat symptom of hearing loss. Users of cochlear implants (CIs) have reported a reduction in tinnitus following implantation for bilateral severe-to-profound deafness. This study assessed the effect of electrical stimulation via a CI on tinnitus in subjects with unilateral deafness and ipsilateral tinnitus who underwent implantation in an attempt to treat tinnitus with the CI. METHODS: Twenty-one subjects who complained of severe intractable tinnitus that was unresponsive to treatment received a CI. Tinnitus loudness was measured with a Visual Analog Scale; loudness percepts were recorded with the device activated and deactivated. Tinnitus distress was measured with the Tinnitus Questionnaire before and after implantation. RESULTS: Electrical stimulation via a CI resulted in a significant reduction in tinnitus loudness (mean +/- SD; 1 year after implantation, 2.4 +/- 1.8; 2 years after implantation, 2.5 +/- 1.9; before implantation, 8.5 +/- 1.3). With the device deactivated, tinnitus loudness was still reduced to between 6.1 and 7.0 over 24 months. The Tinnitus Questionnaire revealed a significant positive effect of CI stimulation. CONCLUSIONS: Unilateral tinnitus resulting from single-sided deafness can be treated with electrical stimulation via a CI. The outcomes of this pilot study demonstrate a new method for treatment of tinnitus in select subjects, perhaps an important new indication for cochlear implantation.

Electric acoustic stimulation of the auditory system: results of a multi-centre investigation.

CONCLUSION: A high rate of hearing preservation during cochlear implantation for electric acoustic stimulation (EAS) is possible, even when surgery is conducted by a number of different surgeons. OBJECTIVES: This study aimed to determine the degree of hearing preservation using surgery for EAS in a European multi-centre clinical investigation. It also aimed to demonstrate the effect of EAS in individuals with residual low frequency hearing, both on speech perception and on subjective quality of life measures. PATIENTS AND METHODS: Eighteen patients with profound high frequency hearing loss were recruited in five participating European centres. Subjects were assessed based on an audiologic test battery, as well as on a subjective hearing aid benefit questionnaire. Each subject underwent attempted hearing preservation cochlear implantation using the MED-EL C40 + device with a Medium electrode. Residual ipsilateral hearing and speech discrimination abilities were assessed at defined intervals up to 12 months after the combined electric-acoustic mode was introduced. RESULTS: Results showed that some degree of hearing preservation was possible in 15718 patients. All subjects showed statistically significant benefit on all three speech perception tests over time. These significant benefits were also reflected in the subjective benefit outcomes.

The experience of bilateral cochlear implantation in a child with LEOPARD syndrome.

We present a 3-year old boy with Leopard syndrome. His clinical manifestations included a congenital bilateral sensorineural hearing loss. He underwent cochlear implantation on the right side at age 1 year and on the left side at age 1.5 years. The patient is doing very well and mainstreamed in a regular pre-school program with a teacher of the deaf and home based speech therapy. Bilateral cochlear implantation in the case of a child with Leopard syndrome can be successful.

Speech Recognition in Noise by Younger and Older Adults: Effects of Age, Hearing Loss, and Temporal Resolution.

OBJECTIVES: Purpose of the present study is to evaluate the effects of aging on temporal resolution and speech understanding in noise. METHODS: Twenty-seven young and 33 older normal hearing adults participated in this study. Temporal resolution was investigated using the Gaps in Noise (GIN) test. Understanding sentences in noise was investigated using a Dutch sentences (LIST) test. RESULTS: Results demonstrated that older adults have significantly worse temporal resolution scores and significantly greater difficulty understanding sentences in noise than younger adults. In the group of older adults, the ability to understand sentences in noise correlated with hearing and age. A stepwise regression analysis showed that age was the best predictor for the speech in noise results. However, temporal resolution correlated with hearing, not with age. Results from the GIN test did not correlate with the results from the LIST test. CONCLUSIONS: The present study shows that with advancing age, both temporal resolution and speech understanding in noise significantly diminish. Temporal resolution correlates with hearing, not age, while speech understanding correlates more with age than hearing. These results could have implications for the outcome of auditory prostheses in older adults, as both diminished temporal resolution and speech understanding have to be taken into account.

Quality-of-life benefit from cochlear implantation in the elderly.

OBJECTIVE: To compare the audiologic results of geriatric patients receiving cochlear implants with younger age groups and to evaluate the quality of life after cochlear implantation in the geriatric population by means of validated quality-of-life questionnaires. STUDY DESIGN: Cross-sectional study involving 89 postlingually deafened cochlear implant subjects. SETTING: Tertiary referral center. PATIENTS: A total of 89 postlingually deafened patients were included in the study, among which were 25 patients who were aged 70 years or older. INTERVENTIONS: All patients received a cochlear implant. Subjects were implanted with either the Laura, Nucleus 24, or Med-el Combi 40+ cochlear implant systems implementing the SPEAK, ACE, CIS, or CIS+ coding strategies. MEAN OUTCOME MEASURES: Speech recognition was determined by means of phonetically balanced monosyllabic word lists. The Hearing Handicap Inventory for Adults, the Glasgow Benefit Inventory, and the scale for the prediction of hearing disability in sensorineural hearing loss were used to quantify the quality of life. RESULTS: Mean audiologic performance for the three groups increased significantly after implantation (p < 0.001). Postoperative audiologic performance of the geriatric population led to useful hearing, but these scores were significantly lower than for the younger age groups (p = 0.002). However, the quality-of-life outcomes for the geriatric group were similar to those of the younger age groups (p = 0.411 for the Hearing Handicap Inventory for Adults; p = 0.886 for the Glasgow Benefit Inventory). CONCLUSION: The results of this study prove that cochlear implantation in the elderly provides improvements in quality of life and speech understanding, similar to those for younger adult cochlear implant recipients.

Binaural interaction in the auditory brainstem response: a normative study.

OBJECTIVE: Binaural interaction can be investigated using auditory evoked potentials. A binaural interaction component can be derived from the auditory brainstem response (ABR-BIC) and is considered evidence for binaural interaction at the level of the brainstem. Although click ABR-BIC has been investigated thoroughly, data on 500 Hz tone-burst (TB) ABR-BICs are scarce. In this study, characteristics of click and 500 Hz TB ABR-BICs are described. Furthermore, reliability of both click and 500 Hz TB ABR-BIC are investigated. METHODS: Eighteen normal hearing young adults (eight women, ten men) were included. ABRs were recorded in response to clicks and 500 Hz TBs. ABR-BICs were derived by subtracting the binaural response from the sum of the monaural responses measured in opposite ears. RESULTS: Good inter-rater reliability is obtained for both click and 500 Hz TB ABR-BICs. The most reliable peak in click ABR-BIC occurs at a mean latency of 6.06 ms (SD 0.354 ms). Reliable 500 Hz TB ABR-BIC are obtained with a mean latency of 9.47 ms (SD 0.678 ms). Amplitudes are larger for 500 Hz TB ABR-BIC than for clicks. CONCLUSION: The most reliable peak in click ABR-BIC occurs at the downslope of wave V. Five hundred Hertz TB ABR-BIC is characterized by a broad positivity occurring at the level of wave V. SIGNIFICANCE: The ABR-BIC is a useful technique to investigate binaural interaction in certain populations. Examples are bilateral hearing aid users, bilateral cochlear implant users and bimodal listeners. The latter refers to the combination of unilateral cochlear implantation and contralateral residual hearing. The majority of these patients have residual hearing in the low frequencies. The current study suggests that 500 Hz TB ABR-BIC may be a suitable technique to assess binaural interaction in this specific population of cochlear implant users.