Julie Arenberg - Academia.edu (original) (raw)

Papers by Julie Arenberg

Cochlear Implants International, Feb 27, 2023

Journal of Speech Language and Hearing Research, Apr 4, 2022

Purpose:This review article provides a theoretical overview of the development of spectral resolu... more Purpose:This review article provides a theoretical overview of the development of spectral resolution in children with normal hearing (cNH) and in those who use cochlear implants (CIs), with an emphasis on methodological considerations. The aim was to identify key directions for future research on spectral resolution development in children with CIs.Method:A comprehensive literature review was conducted to summarize and synthesize previously published behavioral research on spectral resolution development in normal and impaired auditory systems.Conclusions:In cNH, performance on spectral resolution tasks continues to improve through the teenage years and is likely driven by gradual maturation of across-channel intensity resolution. A small but growing body of evidence from children with CIs suggests a more complex relationship between spectral resolution development, patient demographics, and the quality of the CI electrode–neuron interface. Future research should aim to distinguish between the effects of patient-specific variables and the underlying physiology on spectral resolution abilities in children of all ages who are hard of hearing and use auditory prostheses.

American Journal of Audiology, Sep 1, 2022

Purpose:Characterizing and comparing speech recognition development in children with cochlear imp... more Purpose:Characterizing and comparing speech recognition development in children with cochlear implants (CIs) is challenging because of variations in test type. This retrospective cohort study modified the Pediatric Ranked Order Speech Perception (PROSPER) scoring system to (a) longitudinally analyze the speech perception of children with CIs and (b) examine the role of age at CI activation, listening mode (i.e., unilateral or bilateral implantation), and interimplant interval.Method:Postimplantation speech recognition scores from 31 children with prelingual, severe-to-profound hearing loss who received CIs were analyzed (12 with unilateral CI [UniCI], 13 with sequential bilateral CIs [SEQ BiCIs], and six with simultaneous BiCIs). Data were extracted from the Massachusetts Eye and Ear Audiology database. A version of the PROSPER score was modified to integrate the varying test types by mapping raw scores from different tests into a single score. The PROSPER scores were used to construct speech recognition growth curves of the implanted ears, which were characterized by the slope of the growth phase, the time from activation to the plateau onset, and the score at the plateau.Results:While speech recognition improved considerably for children following implantation, the growth rates and scores at the plateau were highly variable. In first implanted ears, later implantation was associated with poorer scores at the plateau (β = −0.15, p = .01), but not growth rate. The first implanted ears of children with BiCIs had better scores at the plateau than those with UniCI (β = 0.59, p = .02). Shorter interimplant intervals in children with SEQ BiCIs promoted faster speech recognition growth of the first implanted ears.Conclusion:The modified PROSPER score could be used clinically to track speech recognition development in children with CIs, to assess influencing factors, and to assist in developing and evaluating patient-specific intervention strategies.Supplemental Material: https://doi.org/10.23641/asha.20113538

Jaro-journal of The Association for Research in Otolaryngology, Jun 7, 2018

Previous psychophysical and modeling studies suggest that cathodic stimulation by a cochlear impl... more Previous psychophysical and modeling studies suggest that cathodic stimulation by a cochlear implant (CI) may preferentially activate the peripheral processes of the auditory nerve, whereas anodic stimulation may preferentially activate the central axons. Because neural degeneration typically starts with loss of the peripheral processes, lower thresholds for cathodic than for anodic stimulation may indicate good local neural survival. We measured thresholds for 99-pulse-per-second trains of triphasic (TP) pulses where the central high-amplitude phase was either anodic (TP-A) or cathodic (TP-C). Thresholds were obtained in monopolar mode from four or five electrodes and a total of eight ears from subjects implanted with the Advanced Bionics CI. When between-subject differences were removed, there was a modest but significant correlation between the polarity effect (TP-C threshold minus TP-A threshold) and the average of TP-C and TP-A thresholds, consistent with the hypothesis that a large polarity effect corresponds to good neural survival. When data were averaged across electrodes for each subject, relatively low thresholds for TP-C correlated with a high Bupper limit^(the pulse rate up to which pitch continues to increase) from a previous study (Cosentino et al. J Assoc Otolaryngol 17:371-382). Overall, the results provide modest indirect support for the hypothesis that the polarity effect provides an estimate of local neural survival.

Trends in hearing, 2022

Speech recognition outcomes are highly variable among pediatric and adult cochlear implant (CI) l... more Speech recognition outcomes are highly variable among pediatric and adult cochlear implant (CI) listeners. Although there is some evidence that the quality of the electrode-neuron interface (ENI) contributes to this large variability in auditory perception, its relationship with speech outcomes is not well understood. Single-channel auditory detection thresholds measured in response to focused electrical fields (i.e., focused thresholds) are sensitive to properties of ENI quality, including electrode-neuron distance, intracochlear resistance, and neural health. In the present study, focused thresholds and speech perception abilities were assessed in 15 children and 21 adult CI listeners. Focused thresholds were measured for all active electrodes using a fast sweep procedure. Speech perception performance was evaluated by assessing listeners’ ability to identify vowels presented in /h-vowel-d/ context. Consistent with prior literature, focused thresholds were lower for children than for adults, but vowel identification did not differ significantly across age groups. Higher across-array average focused thresholds, which may indicate a relatively poor ENI quality, were associated with poorer vowel identification scores in both children and adults. Adult CI listeners with longer durations of deafness had higher focused thresholds. Findings from this study demonstrate that poor-quality ENIs may contribute to reduced speech outcomes for pediatric and adult CI listeners. Estimates of ENI quality (e.g., focused thresholds) may assist in developing customized programming interventions that serve to improve the transmission of spectral cues that are important in vowel identification.

Trends in hearing, 2019

Modeling data suggest that sensitivity to the polarity of an electrical stimulus may reflect the ... more Modeling data suggest that sensitivity to the polarity of an electrical stimulus may reflect the integrity of the peripheral processes of the spiral ganglion neurons. Specifically, better sensitivity to anodic (positive) current than to cathodic (negative) current could indicate peripheral process degeneration or demyelination. The goal of this study was to characterize polarity sensitivity in pediatric and adult cochlear implant listeners (41 ears). Relationships between polarity sensitivity at threshold and (a) polarity sensitivity at suprathreshold levels, (b) age-group, (c) preimplantation duration of deafness, and (d) phoneme perception were determined. Polarity sensitivity at threshold was defined as the difference in single-channel behavioral thresholds measured in response to each of two triphasic pulses, where the central high-amplitude phase was either cathodic or anodic. Lower thresholds in response to anodic than to cathodic pulses may suggest peripheral process degeneration. On the majority of electrodes tested, threshold and suprathreshold sensitivity was lower for anodic than for cathodic stimulation; however, dynamic range was often larger for cathodic than for anodic stimulation. Polarity sensitivity did not differ between child-and adult-implanted listeners. Adults with long preimplantation durations of deafness tended to have better sensitivity to anodic pulses on channels that were estimated to interface poorly with the auditory nerve; this was not observed in the child-implanted group. Across subjects, duration of deafness predicted phoneme perception performance. The results of this study suggest that subject-and electrode-dependent differences in polarity sensitivity may assist in developing customized cochlear implant programming interventions for child-and adult-implanted listeners.

Hearing Research, Feb 1, 2001

The electrically evoked middle latency response (EMLR) is a potentially useful measure of activat... more The electrically evoked middle latency response (EMLR) is a potentially useful measure of activation of the auditory system by a cochlear prosthesis. The present study compared cochlear prosthesis thresholds determined using EMLR with thresholds determined for psychophysical detection and for spike activity in cortical neurons. In systemically deafened guinea pigs, the difference between EMLR and psychophysical threshold level varied, with differences ranging from 34.6 dB (EMLR threshold more sensitive) to +10.7 dB (psychophysical threshold more sensitive) across animals and phase durations. Threshold differences between EMLR and auditory cortex neural spike responses were similar in magnitude and range (36 to +15 dB) to those seen for EMLR vs. psychophysical thresholds. These ranges are comparable to the behavioral operating range for a given condition. In 3 of 12 subjects, the EMLR was absent for some or all electrode configurations tested, even at levels well above the threshold for psychophysical detection or cortical neuronal response. These results suggest that neither the EMLR thresholds nor cortical neuronal spike thresholds are an adequate substitute for psychophysical measures of threshold. While not sufficient for use in place of psychophysical measures, EMLR threshold level is strongly correlated with psychophysical threshold level across subjects (R 2 = 0.82). Interestingly, plots of thresholds vs. phase duration were roughly parallel for psychophysical and EMLR thresholds, in contrast to the divergence of psychophysical and more peripheral (e.g., electrically evoked auditory brainstem response) evoked neural threshold vs. phase duration functions.

Jaro-journal of The Association for Research in Otolaryngology, Mar 25, 2019

Cochlear implant (CI) programming is similar for all CI users despite limited understanding of th... more Cochlear implant (CI) programming is similar for all CI users despite limited understanding of the electrodeneuron interface (ENI). The ENI refers to the ability of each CI electrode to effectively stimulate target auditory neurons and is influenced by electrode position, neural health, cochlear geometry, and bone and tissue growth in the cochlea. Hearing history likely affects these variables, suggesting that the efficacy of each channel of stimulation differs between children who were implanted at young ages and adults who lost hearing and received a CI later in life. This study examined whether ENI quality differed between early-implanted children and late-implanted adults. Auditory detection thresholds and most comfortable levels (MCLs) were obtained with monopolar and focused electrode configurations. Channel-to-channel variability and dynamic range were calculated for both types of stimulation. Electrical field imaging data were also acquired to estimate levels of intracochlear resistance. Children exhibited lower average auditory perception thresholds and MCLs compared with adults, particularly with focused stimulation. However, neither dynamic range nor channel-to-channel threshold variability differed between groups, suggesting that children's range of perceptible current was shifted downward. Children also demonstrated increased intracochlear resistance levels relative to the adult group, possibly reflecting greater ossification or tissue growth after CI surgery. These results illustrate physical and perceptual differences related to the ENI of early-implanted children compared with lateimplanted adults. Evidence from this study demonstrates a need for further investigation of the ENI in CI users with varying hearing histories.

Trends in hearing, 2018

Children's performance on psychoacoustic tasks improves with age, but inadequate auditory input m... more Children's performance on psychoacoustic tasks improves with age, but inadequate auditory input may delay this maturation. Cochlear implant (CI) users receive a degraded auditory signal with reduced frequency resolution compared with normal, acoustic hearing; thus, immature auditory abilities may contribute to the variation among pediatric CI users' speech recognition scores. This study investigated relationships between age-related variables, spectral resolution, and vowel identification scores in prelingually deafened, early-implanted children with CIs compared with normal hearing (NH) children. All participants performed vowel identification and the Spectral-temporally Modulated Ripple Test (SMRT). Vowel stimuli for NH children were vocoded to simulate the reduced spectral resolution of CI hearing. Age positively predicted NH children's vocoded vowel identification scores, but time with the CI was a stronger predictor of vowel recognition and SMRT performance of children with CIs. For both groups, SMRT thresholds were related to vowel identification performance, analogous to previous findings in adults. Sequential information analysis of vowel feature perception indicated greater transmission of duration-related information compared with formant features in both groups of children. In addition, the amount of F2 information transmitted predicted SMRT thresholds in children with NH and with CIs. Comparisons between the two CIs of bilaterally implanted children revealed disparate task performance levels and information transmission values within the same child. These findings indicate that adequate auditory experience contributes to auditory perceptual abilities of pediatric CI users. Further, factors related to individual CIs may be more relevant to psychoacoustic task performance than are the overall capabilities of the child.

Ear and Hearing, Jan 14, 2020

The primary objective of this study was to quantify local (within ear) and global (between ear) v... more The primary objective of this study was to quantify local (within ear) and global (between ear) variation in the cochlear implant (CI) electrode-neuron interface (ENI) using the electrically evoked compound action potential (ECAP). We tested the hypothesis that, within an ear, ECAP measures can be used to identify channels with presumed good and poor ENIs, which may be influenced by a combination of spiral ganglion neuron (SGN) density, electrode position, and cochlear resistivity. We also hypothesized that ECAP responses would reflect age-related differences in the global quality of the ENI between younger and older listeners who theoretically differ in SGN density. Design: Data were obtained from 18 implanted ears (13 individuals) with Advanced Bionics HiRes 90K devices. Six participants (8 ears) were adolescents or young adults (age range: 14-32 years), and 7 participants (10 ears) were older adults (age range: 54-88 years). In each ear, single-channel auditory detection thresholds were measured on channels 2 through 15 in response to a spatially focused electrode configuration (steered quadrupolar; focusing coefficient = 0.9). ECAP amplitudes, amplitude growth function (AGF) slopes, and thresholds were assessed on a subset of channels in each ear in response to three interphase gaps (0, 7, and 30 µs). ECAP peak amplitudes were assessed on all channels between 2 and 15. AGFs and ECAP thresholds were measured on the two nonadjacent channels with the lowest and highest focused behavioral thresholds in each ear. ECAP responses were compared across low-and high-threshold channels and between younger and older CI listeners. Results: Channels that were estimated to interface poorly with the auditory nerve (i.e., high-focused-threshold channels) had steeper ECAP AGF slopes, smaller dynamic ranges, and higher ECAP thresholds than channels with low focused thresholds. Younger listeners had steeper ECAP AGF slopes and larger ECAP peak amplitudes than older listeners. Moreover, younger listeners showed greater interphase gap sensitivity for ECAP amplitude than older listeners. Conclusions: ECAP responses may be used to quantify both local (within ear) and global (between ear) variation in the quality of the ENI. Results of this study support future investigation into the use of ECAP responses in site-selection CI programming strategies. The present results also support a growing body of evidence suggesting that adolescents and young adults with CIs may have denser populations of functional SGNs relative to older adults. Potential differences in global SGN integrity between younger and older listeners warrant investigation of optimal CI programming interventions based on their divergent hearing histories.

Ear and Hearing, Mar 1, 2019

Objectives-Channel interaction, the stimulation of overlapping populations of auditory neurons by... more Objectives-Channel interaction, the stimulation of overlapping populations of auditory neurons by distinct cochlear implant (CI) channels, likely limits the speech perception performance of CI users. This study examined the role of vocoder-simulated channel interaction in the ability of children and adults with normal hearing to recognize spectrally degraded speech. The primary aim was to determine the interaction between number of processing channels and degree of simulated channel interaction on phoneme identification performance as a function of age for children with normal hearing (cNH), and to relate those findings to adults with normal hearing (aNH) and to CI users. Design-Medial vowel and consonant identification of cNH (age 8-17 years) and young aNH were assessed under six (for children) or nine (for adults) different conditions of spectral degradation. Stimuli were processed using a noise-band vocoder with 8, 12, and 15 channels and synthesis filter slopes of 15 (aNH only), 30 and 60 dB/octave (all NH subjects). Steeper filter slopes (larger numbers) simulated less electrical current spread and therefore less channel interaction. Spectrally degraded performance of the NH listeners was also compared to the unprocessed phoneme identification of school-aged children and adults with CIs. Results-Spectrally degraded phoneme identification improved as a function of age for cNH. For vowel recognition, cNH exhibited an interaction between the number of processing channels and vocoder filter slope, whereas aNH did not. Specifically, for cNH, increasing the number of processing channels only improved vowel identification in the steepest filter slope condition. Additionally, cNH were more sensitive to changes in filter slope. As the filter slopes increased, cNH continued to receive vowel identification benefit beyond where aNH performance plateaued orreached ceiling. For all NH participants, consonant identification improved with increasing filter slopes, but was unaffected by the number of processing channels. Although cNH made more phoneme identification errors overall, their phoneme error patterns were similar to aNH.

Frontiers in Neuroscience, Jan 15, 2019

Despite being considered one of the most successful neural prostheses, cochlear implants (CIs) pr... more Despite being considered one of the most successful neural prostheses, cochlear implants (CIs) provide recipients with a wide range of speech perception performance. While some CI users can understand speech in the absence of visual cues, other recipients exhibit more limited speech perception. Cognitive skills have been documented as a contributor to complex auditory processing, such as language understanding; however, there are no normative data for existing standardized clinical tests assessing cognitive abilities in CI users. Here, we assess the impact of modality of presentation (i.e., auditory-visual versus visual) for the administration of working memory tests in high-performing CI users in addition to measuring processing speed, cognitive efficiency and intelligence quotient (IQ). Second, we relate performance on these cognitive measures to clinical CI speech perception outcomes. Methods: Twenty one post-lingually deafened, high-performing, adult CI users [age range: 52-88 years; 3 unilateral CI, 13 bimodal (i.e., CI with contralateral hearing aid), 5 bilateral CI] with clinical speech perception scores (i.e., AzBio sentences in quiet for the first-ear CI) of ≥60% were recruited. A cognitive test battery assessing auditoryvisual working memory (AVWM), visual working memory (VWM), processing speed, cognitive efficiency and IQ was administered, in addition to clinical measures of speech perception in quiet (i.e., AzBio sentences in quiet). AzBio sentences were assessed in two conditions: first-ear CI only, and best-aided everyday wearing condition. Subjects also provided self-reported measures of performance and benefit from their CI using standardized materials, including the Glasgow Benefit Inventory (GBI) and the Nijmegen Cochlear Implant questionnaire (NCIQ). Results: High-performing CI users demonstrated greater VWM than AVWM recall. VWM was positively related to AzBio scores when measured in the first-ear CI only. AVWM, processing speed, cognitive efficiency, and IQ did not relate to either measure of speech perception (i.e., first-ear CI or best-aided conditions). Subjects' self-reported benefit as measured by the GBI predicted best-aided CI speech perception performance. Conclusion: In high-performing CI recipients, visual presentation of working memory tests may improve our assessment of cognitive function.

Trends in hearing, 2023

Dynamic focusing cochlear implant strategies aim to emulate normal cochlear excitation patterns b... more Dynamic focusing cochlear implant strategies aim to emulate normal cochlear excitation patterns by varying the degree of current focusing as a function of input level. Results on the speech perception benefits of these strategies have been mixed. In previous studies, channel interaction coefficients ( K), which mediate the relationship between current level and degree of focusing, were fixed across channels and participants. Fixing K without accounting for channel interaction and the current required to accurately stimulate target neurons may elicit suboptimal loudness growth and speech perception. This study tested whether individualizing K improved speech perception relative to fixed- K and monopolar strategies. Fourteen ears of implanted adults were programmed with 14-channel strategies matched on pulse duration, pulse rate, filtering, and loudness. Sentence recognition and vowel identification was measured at 60 dB SPL equivalent in quiet and four-talker babble. On the group level, speech recognition in quiet and noise was similar between strategies. On the individual level, there were participants who benefitted with dynamic focusing strategies for speech perception in noise. Patterns of benefit were generally unclear, beyond associations between focused thresholds, duration of hearing loss, and individual- K benefit. Participants rated dynamic focusing like monopolar in clarity and ease of listening. Almost all participants expressed their willingness to use the strategies in a take-home trial. These results suggest that while individualizing K does not benefit all, there are individuals who benefit, for which the electrode–neuron interface may play a role. Future studies will evaluate acclimatization of dynamic focusing strategies using take-home trials.

Otology & Neurotology, Nov 14, 2022

PLOS ONE, Dec 13, 2021

The relationship between electrode-nerve interface (ENI) estimates and inter-subject differences ... more The relationship between electrode-nerve interface (ENI) estimates and inter-subject differences in speech performance with sequential and simultaneous channel stimulation in adult cochlear implant listeners were explored. We investigated the hypothesis that individuals with good ENIs would perform better with simultaneous compared to sequential channel stimulation speech processing strategies than those estimated to have poor ENIs.

Acta Acustica United With Acustica, Sep 1, 2018

European Archives of Oto-rhino-laryngology, Aug 1, 1997

There is a paucity of studies regarding the regulation of vestibular blood flow (VBF), despite th... more There is a paucity of studies regarding the regulation of vestibular blood flow (VBF), despite the possibility that vascular alterations may contribute to specific vestibulopathies. The current experiments used the Mongolian gerbil as an animal model since it provides easy surgical access to the vestibular end-organs and has been previously used for physiologic studies involving inner ear function. VBF changes were measured in the posterior semicircular canal using laser Doppler flowmetry following round window membrane (RWM) application of the nitric oxide donor 1, 3-propanediamine-N-[4-1-(3-aminopropyl)-2-hydroxy-2-nitrosohydrazi no] butyl (spermine NONOate; SPNO) as a vasodilator. The specificity of the responses induced was tested via pretreatment with an NO scavenger, 2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazonline-1-oxyl-3-oxide (carboxy-PTIO; cPTIO). cPTIO, SPNO, vehicle (control) or cPTIO/SPNO were applied to the RWM, during which blood pressure and VBF were monitored for baseline, treatment, and recovery conditions. Results showed concentration-dependent increases in flow, probably resulting from NO's vasodilatory action on local vasculature. cPTIO pretreatment was found to attenuate SPNO-induced VBF increases. These findings support a role of NO in maintaining the vestibular microcirculation.

Ear and Hearing, Nov 1, 2018

The standard, monopolar (MP) electrode configuration used in commercially available cochlear impl... more The standard, monopolar (MP) electrode configuration used in commercially available cochlear implants (CI) creates a broad electrical field, which can lead to unwanted channel interactions. Use of more focused configurations, such as tripolar and phased array, has led to mixed results for improving speech understanding. The purpose of the present study was to assess the efficacy of a physiologically inspired configuration called dynamic focusing, using focused tripolar stimulation at low levels and less focused stimulation at high levels. Dynamic focusing may better mimic cochlear excitation patterns in normal acoustic hearing, while reducing the current levels necessary to achieve sufficient loudness at high levels. Design: Twenty postlingually deafened adult CI users participated in the study. Speech perception was assessed in quiet and in a four-talker babble background noise. Speech stimuli were closed-set spondees in noise, and medial vowels at 50 and 60 dB SPL in quiet and in noise. The signal to noise ratio was adjusted individually such that performance was between 40 and 60% correct with the MP strategy. Subjects were fitted with three experimental strategies matched for pulse duration, pulse rate, filter settings, and loudness on a channel-by-channel basis. The strategies included 14 channels programmed in MP, fixed partial tripolar (σ = 0.8), and dynamic partial tripolar (σ at 0.8 at threshold and 0.5 at the most comfortable level). Fifteen minutes of listening experience was provided with each strategy before testing. Sound quality ratings were also obtained. Results: Speech perception performance for vowel identification in quiet at 50 and 60 dB SPL and for spondees in noise was similar for the three tested strategies. However, performance on vowel identification in noise was significantly better for listeners using the dynamic focusing strategy. Sound quality ratings were similar for the three strategies. Some subjects obtained more benefit than others, with some individual differences explained by the relation between loudness growth and the rate of change from focused to broader stimulation. Conclusions: These initial results suggest that further exploration of dynamic focusing is warranted. Specifically, optimizing such strategies on an individual basis may lead to improvements in speech perception for more adult listeners and improve how CIs are tailored. Some listeners may also need a longer period of time to acclimate to a new program.

Jaro-journal of The Association for Research in Otolaryngology, Apr 4, 2019

The physiological integrity of spiral ganglion neurons is presumed to influence cochlear implant ... more The physiological integrity of spiral ganglion neurons is presumed to influence cochlear implant (CI) outcomes, but it is difficult to measure neural health in CI listeners. Modeling data suggest that, when peripheral processes have degenerated, anodic stimulation may be a more effective neural stimulus than cathodic stimulation. The primary goal of the present study was to evaluate the emerging theory that polarity sensitivity reflects neural health in CI listeners. An ideal in vivo estimate of neural integrity should vary independently of other factors known to influence the CI electrode-neuron interface, such as electrode position and tissue impedances. Thus, the present analyses quantified the relationships between polarity sensitivity and (1) electrode position estimated via computed tomography imaging, (2) intracochlear resistance estimated via electrical field imaging, and (3) focused (steered quadrupolar) behavioral thresholds, which are believed to reflect a combination of local neural health, electrode position, and intracochlear resistance. Eleven adults with Advanced Bionics devices participated. To estimate polarity sensitivity, electrode-specific behavioral thresholds in response to monopolar, triphasic pulses where the central high-amplitude phase was either anodic (CAC) or cathodic (ACA) were measured. The polarity effect was defined as the difference in threshold response to the ACA compared to the CAC stimulus. Results indicated that the polarity effect was not related to electrode-to-modiolus distance, electrode scalar location, or intracochlear resistance. Large, positive polarity effects, which may indicate SGN degeneration, were associated with relatively high focused behavioral thresholds. The polarity effect explained a significant portion of the variation in focused thresholds, even after controlling for electrode position and intracochlear resistance. Overall, these results provide support for the theory that the polarity effect may reflect neural integrity in CI listeners. Evidence from this study supports further investigation into the use of polarity sensitivity for optimizing individual CI programming parameters.

Annals of the New York Academy of Sciences, Dec 1, 1997

CMV infections are classified as two major types: the first is clinically seen at birth and is sy... more CMV infections are classified as two major types: the first is clinically seen at birth and is systemic in nature, and the second is not clinically apparent at birth and is termed asymptomatic or subclinical. Importantly, both types of CMV infections have reported otologic sequelae ...