Characterizing responses from auditory cortex in young people with several years of cochlear implant experience

from Clinical Neurophysiology

Objective
To determine if cortical responses evoked by a cochlear implant in children who are deaf differ from normal and to characterize these differences in children who achieve good versus fair speech perception outcomes post-implantation.

Methods
Late latency-evoked potential responses were recorded at 28 scalp locations in 16 children who were deaf from infancy and experienced cochlear implant users. Speech perception measures indicated that 8 had good scores and 8 had fair scores. In each child, responses were evoked by 36 ms electrical pulse trains delivered from a single-implant electrode at the apical and basal ends of the array and by 36 ms tone bursts (0.5, 2, and 6 kHz). Responses to the tone bursts were also recorded in 14 age-matched children with normal hearing.

Results
We found (1) a dominant positive wave in all implant users and (2) a larger than normal negative amplitude peak in users with fair speech perception scores which had similar scalp topography to N1 but did not show the expected changes in amplitude with stimulus frequency.

Conclusions
Late latency-evoked potential responses in children using cochlear implants reflect abnormal and/or immature patterns of cortical activity.

Significance
Limitations in auditory skills with a cochlear implant in children may be due to developmental processes in the cortex which are either slow to mature or which mature abnormally.

Long-Term Prognosis of Steroid-Dependent Sensorineural Hearing Loss

from Audiology & Neuro-Otology

We report on the long-term follow-up of 15 patients with steroid-dependent sensorineural hearing loss (SDSNHL), which was steroid dose dependent. We classified the patients into 2 groups: group A consisted of 6 patients with systemic SDSNHL, and group B consisted of 9 patients with inner-ear-specific SDSNHL without systemic disease. Group B patients were further classified as patients with slowly or rapidly progressive hearing loss. The yearly rate of hearing deterioration was greater in group B than in group A. Thus, the long-term hearing prognosis of patients in group B was worse than those in group A. Although SDSNHL may have immune-related origins, we hypothesize that hearing deterioration may be caused by proinflammatory cytokines because many of our cases exhibited abnormal immunological laboratory values and because many of these cases responded favorably to steroid treatment.

Cross-Cultural Adaptation and Validation of the Voice Handicap Index Into Greek

from the Journal of Voice

The objective was to culturally adapt and validate the Voice Handicap Index (VHI) to the Greek language. The study design used was a psychometric analysis. The VHI was translated into Greek with cultural adaptations to accommodate certain words. The translated version was then completed by 67 subjects with various voice disorders and by a control group of 79 subjects. All the participants also completed a self-rating scale regarding the severity of their voice disorder. Statistical analyses demonstrated high internal consistency and high test-retest reliability both for the overall VHI score and for the functional, physical, and emotional domains of the VHI. A moderate correlation was found between the VHI and the self-rating severity scale. The subjects in the control group had lower scores compared to the subjects with voice disorders for the overall VHI score and for the three domains. Based on the internal consistency values and the test-retest reliability, the Greek version of VHI is a valid and reliable measure for use by Greek subjects with voice disorders.

Biophysical Method May Help To Recover Hearing

from Medical News Today.com

Scientists based in Switzerland and South Africa have created a biophysical methodology that may help to overcome hearing deficits, and potentially remedy even substantial hearing loss. The authors propose a method of retuning functioning regions of the ear to recognize frequencies originally associated with damaged areas. Details are published August 29th in the open- access journal PLoS Computational Biology.

Audiological Application Criteria for Implantable Hearing Aid Devices: A Clinical Experience at the Nijmegen ORL Clinic

from Laryngoscope

Abstract:
Objectives/Hypothesis: To define audiological application criteria for different implantable hearing aid devices.

Study Design: Retrospective study.

Methods: Comparisons were made between aided speech recognition scores obtained at conversational level (65 dB) in patients with the Vibrant Soundbridge (VSB) (n = 22), the Otologics middle ear transducer (MET) (n = 10), conventional hearing aids (behind-the-ears) (n = 47), and cochlear implants (CIs) (n = 123).

Results: In relation to hearing loss, only for mild hearing loss, speech recognition scores with VSB were comparable to that with conventional hearing aids. In the Otologics MET users, speech recognition scores were comparable with those of the conventional hearing aid users until a mean hearing loss of about 75 dB HL. At a sensorineural hearing loss of about 65 dB HL or more, the Otologics MET users have better speech recognition scores than the VSB users. For comparison with CI users, we followed a more conservative approach. In 90% of the users of a CI, speech recognition scores were better than those in: 1) patients with a conventional hearing aid and a mean hearing loss of about 95 dB HL or worse; 2) patients with an Otologics MET and a mean hearing loss of 85 dB HL or worse.

Conclusions: Patients fitted with a VSB or an Otologics MET middle ear implant do not demonstrate better speech recognition scores than patients fitted with today’s conventional hearing aids. Results might even been worse. However, the VSB and Otologics MET are a good option in patients with moderate (VSB) to severe (Otologics MET) sensorineural hearing loss and external otitis.

Characteristics of Age-Related Changes in Cultured Human Vocal Fold Fibroblasts

from Laryngoscope

Abstract:
Objectives/Hypothesis: Normal human vocal fold fibroblast (hVFF) primary cell lines are unavailable commercially and are very difficult to acquire, subsequently little is known about their characteristics. The purpose of this study was to compare the morphological and proliferation characteristics and gene expression of hVFFs from different aged donors.

Study Design: In vitro.

Methods: We developed three normal hVFF primary cell lines from donors aged 21 (21T), 59 (59T) and 79 (79T) years. We characterized their morphological features, proliferative abilities, telomere lengths, and their functional gene expression by quantitative real-time PCR.

Results: The 21T line maintained a typical spindle shape until passage 14 whereas 59T and 79T changed morphology to wider, shorter cells at passage 7. Proliferation rates were constant for the 21T through passage 14; 59T’s proliferative half-life was passage 9, whereas 79T maintained lower proliferation rates from passage 4. Gene expression levels for fibronectin, collagen I, collagen VI, procollagen I and elastin demonstrated similar patterns for all lines, however, relative amounts decreased with the age of donor. Telomere lengths did not show differences related with donor age.

Conclusions: hVFF primary cultures have limited proliferative capacity. The morphology, proliferation, differentiation, and gene expression levels of VFF can be affected by age, but senescence patterns were similar across the ages.

Does Hyaluronic Acid Distribution in the Larynx Relate to the Newborn’s Capacity for Crying?

from Laryngoscope

Abstract:
Objectives/Hypothesis: The newborn is heavily dependent on voice communication and therefore has relatively higher vocal demands and expenditures than the adult, the loudness output per mass performance exceeds that of the adult, and the newborn larynx exhibits significant histological and biochemical differences. The neonatal larynx is capable of sustaining relatively greater pitch and loudness than the adult over longer periods of time. This ability may be related to a more compact arrangement of collagen within the lamina propria, less interstitial space, and a uniform distribution of hyaluronic acid (HA). As HA is the primary determinant of vocal fold viscosity and water content, the distribution of HA in the superficial portion of the neonatal vocal fold is hypothesized to be related to newborn crying endurance. Our objective was to examine the histological structure and the quantity and arrangement of HA within the lamina propria of the pediatric larynx and review the relevant physiology of hyaluronic acid and its impact on voice production.

Study Design: Histological and digital subtraction analysis.

Methods: Intact, neonatal larynges were sourced from fresh cadaveric specimens. Trichrome stain was used to assess the collagen content and location in the tissues. HA was stained using a colloidal iron staining technique with and without incubation with bovine testicular hyaluronidase. Average optical density was calculated in tissue before and after treatment with hyaluronidase, and the stain intensity ratio was calculated.

Results: A total of 14 larynges were suitable for examination, eight males and six females. Histological examination revealed a uniform appearance of the vocalfold without evidence of a distinct vocal ligament or layered structure. Colloidal iron staining revealed an even distribution of HA throughout the vocal fold with no significant difference between quadrants. Images of the colloidal iron-stained tissue had a mean pixel intensity of 82 of 255. Slides of vocal fold tissue treated with hyaluronidase revealed a pixel intensity of 106 of 255 for a 22% mean difference in stain intensity (P < .01).

Conclusions: The identification of the layered structure of the adult lamina propria has raised a number of questions as to the development and purpose of the human larynx. Based on histological observations from the current study, possible explanations for the physiological differences include differences in the distribution and tissue concentration of HA and consequently dynamic viscosity, oncotic affinity for water, and less intercellular space in the superficial lamina propria.

The Intensity-Pitch Relation Revisited: Monopolar Versus Bipolar Cochlear Stimulation

from Laryngoscope

Abstract:
Objective/Hypothesis: The very high speech perception scores now being achieved with cochlear implants have led to demands for similar levels of achievement in music perception and perception in noisy environments. One of the crucial factors in these fields is pitch perception. The aim of the present study was to investigate the extent to which pitch perception is influenced by the intensity of the stimulus, through the use of different stimulation modes (monopolar, bipolar) and different electrodes (lateral and perimodiolar).

Study Design: Sixteen postlingually deafened patients with an average implant use of 3.1 years were included in this study. All patients were using a Cochlear (CI24M, CI24R, CI24RE) cochlear implant.

Methods: Subjects were asked to compare the pitch of an intensity-constant reference tone with the pitch of a test tone of varying intensity. The test was repeated for apical, mediocochlear, and basal channel locations, and also for monopolar and bipolar stimulation.

Results: It was found that in monopolar stimulation 87.5% and in bipolar stimulation 85.7% of the patients perceived a clear pitch change with changing intensity of the stimulus (Spearman correlation coefficients r 0.3, respectively). A total of 73.1% of these patients perceived lower pitches with increasing intensity, 26.9% reported the opposite effect. No statistically significant difference in the intensity-pitch correlation could be found between mono- and bipolar stimulation. Neither the mean dynamic range nor the type of electrode used was found to be related to the correlation coefficient.

Conclusion: Although the majority of today’s cochlear implant recipients perform well and the intensity-pitch relation in cochlear implant recipients is still poorly understood, rising demands on speech-coding strategies may soon make a compensation of the pitch shifts desirable. Although the results of our study tend to argue against a peripheral mechanism, the exact origin of this phenomenon remains unclear.

(C) The American Laryngological, Rhinological & Otological

Treatment Responsiveness of the Singing Voice Handicap Index

from Laryngoscope

Abstract:
Objectives/Hypothesis: To examine the responsiveness of the previously validated Singing Voice Handicap Index (SVHI) to treatment related changes in patients’ singing voice.

Study Design: Prospective.

Methods: Thirty singing patients at a tertiary voice clinic prospectively completed the Voice Handicap Index and SVHI at their initial presentation, pretreatment, and posttreatment.

Results: Patients had lower SVHI scores posttherapy compared with the initial SVHI scores (P <= .001, paired t-test). The change in SVHI scores from initial to posttreatment evaluation was greater than the change from initial to pretreatment evaluation (P < .001, paired t-test). The Spearman correlation of the Voice Handicap Index difference with the SVHI difference before and after treatment was 0.71 (P < .001).

Conclusion: The SVHI measures changes in patients’ singing vocal health status resulting from treatment and the change correlates with that of other validated instruments.

Estimation of Night Traffic Noise Levels

from Acta Acoustica united with Acustica

A method to estimate levels of night traffic noise Ln is presented with the assumption that the day levels Ld are known, applying the expression Ln = Ld-Ld-n, where Ld-n is the difference between Ld and Ln. This procedure implies the direct measurement of Ld-n in some streets of the city by means of long-term measurements (more than 24 hours) and the extrapolation of these results to the remaining streets. The estimation of Ln using this procedure allows a substantial saving of resources as it does not demand the repetition of all measurement points used in determining Ld, given that Ld-n only depends on traffic variation. It is demonstrated that Ld-n parameter can follow a normal distribution, and that statistically it is not a constant value for all streets in a given city but it is necessary to establish at least two different categories of streets to enable accurate estimation.

Human Response to a Step Change in Noise Exposure Following the Opening of a New Railway Extension in Hong Kong

from Acta Acoustica united with Acustica

A study was undertaken to determine the change in exposure of dwellings to road traffic and railway noise and the residents’ annoyance reactions in a new town in Hong Kong following the opening of an 11.4-km railway extension line. The acoustic changes were determined by noise mapping and validated by field measurements. Social surveys were performed six months before, three months following and one year after operation of the railway. The results show that despite railway noise and a small increase in total noise exposure, the annoyance of the residents decreased with time during the study period, showing that annoyance was not significantly related to noise levels or the magnitude of change in exposure level. The results of path analysis show that factors affecting annoyance reactions changed during the study period covering different stages before and after operation of the railway. While the current research design does not provide temporal human response data long enough to ascertain whether the annoyance reaction just before opening of the railway was an overreaction, the study has nonetheless demonstrated that annoyance did attenuate over time. Possible factors affecting human annoyance reactions and implications for environmental management are examined in the paper.

Language-Selective Interference with Long-Term Memory for Musical Pitch

from Acta Acoustica united with Acustica

This study examines linguistic influences on musical pitch processing and provides evidence for a form of language-selective interference with absolute-pitch (AP) memory. We show that voiced solfege syllables whose fundamental frequencies and harmonic structures are digitally shifted to precisely map onto a mismatched musical note can selectively interfere with pitch identification by some but not other AP musicians. Interference diminishes as the stimulus spectrum is increasingly lowpass filtered to remove its broadband speech features. Time reversal of mismatched pitch-syllable “hybrids”, which distorts their phase spectra but leaves their amplitude spectra intact, also substantially reduces interference. These findings support recent theories of AP encoding that propose an intrinsic association between linguistic cues and stored pitch representations in extraction and accurate labeling of pitch from long-term memory.

Temporal Resolution of Hearing Probed by Bandwidth Restriction

from Acta Acoustica united with Acustica

This work investigates the temporal resolution of human hearing through its discrimination of the time constant of low-pass filtering applied to a periodic signal. While restricting the bandwidth affects both the amplitude spectrum and temporal definition of the signal, the direct amplitude changes in this experiment fall below their just noticeable differences. The discrimination therefore seems to be sensitive to phase in addition to spectral amplitude differences. An upperbound of τ ≈ 5 μs was obtained for the threshold time constant, showing that human temporal resolution extends down to time scales shorter than found in the past.

Auralization. Fundmamentals of Acoustics, Modelling, Simulation, Algorithms and Acoustic Virtual Reality

from Acta Acoustica united with Acustica

No abstract available.

Earwax Removal: National Guidelines Released

from Medical News Today.com

The American Academy of Otolaryngology – Head and Neck Surgery Foundation (AAO-HNSF) will issue the first comprehensive clinical guidelines to help health care practitioners identify patients with cerumen (commonly referred to as earwax) impaction. The guidelines emphasize evidence-based management of cerumen impaction by clinicians, and inform patients of the purpose of ear wax in hearing health.