Monthly Archives: March 2011
Exploring the Factors Influencing Discontinued Hearing Aid Use in Patients With Unilateral Cochlear Implants
Studies have shown that unilateral cochlear implant users who have residual hearing in the contralateral ear can benefit from combining a hearing aid in the nonimplanted ear with their cochlear implant. The purpose of this study was to better understand the factors influencing decision making by adults. Adults who had discontinued hearing aid use shortly after cochlear implantation were selected from one Canadian cochlear implant program. An examination of hearing aid use revealed that of 96 patients, who used hearing aids preimplant, 49 had discontinued hearing aid use. Patient perspectives on the decision and experience of combining a hearing aid and a cochlear implant were collected through 12 individual semistructured interviews. The interviews were analyzed qualitatively to identify key themes. Questionnaires, based on the interview findings, were developed and sent to the 49 adults to further explore the factors affecting hearing aid decisions. Interview and questionnaire findings from 28 adults indicated that three factors primarily influenced patients’ decision to discontinue hearing aid use: their perceptions of the experience with hearing aids prior to implantation, their views of superiority of a unilateral cochlear implant in comparison with hearing aids, and their perceptions of interference with sound quality when a cochlear implant and hearing aid were combined. This study provides information about patient perceptions, experiences, and understanding of the potential difficulties of a bimodal fitting that may assist clinicians in pre- and postimplant counseling.
Normal Adult Aging and the Contextual Influences Affecting Speech and Meaningful Sound Perception
It is widely accepted that hearing loss increases markedly with age, beginning in the fourth decade ISO 7029 (2000). Age-related hearing loss is typified by high-frequency threshold elevation and associated reductions in speech perception because speech sounds, especially consonants, become inaudible. Nevertheless, older adults often report additional and progressive difficulties in the perception and comprehension of speech, often highlighted in adverse listening conditions that exceed those reported by younger adults with a similar degree of high-frequency hearing loss (Dubno, Dirks, & Morgan) leading to communication difficulties and social isolation (Weinstein & Ventry). Some of the age-related decline in speech perception can be accounted for by peripheral sensory problems but cognitive aging can also be a contributing factor. In this article, we review findings from the psycholinguistic literature predominantly over the last four years and present a pilot study illustrating how normal age-related changes in cognition and the linguistic context can influence speech-processing difficulties in older adults. For significant progress in understanding and improving the auditory performance of aging listeners to be made, we discuss how future research will have to be much more specific not only about which interactions between auditory and cognitive abilities are critical but also how they are modulated in the brain.
Using Concha Electrodes to Measure Cochlear Microphonic Waveforms and Auditory Brainstem Responses
During electrocochleography, that is, ECochG or ECoG, a recording electrode can be placed in the ear canal lateral to the tympanic membrane. We designed a concha electrode to record both sinusoidal waveforms of cochlear microphonics (CMs) and auditory brainstem responses (ABRs). The amplitudes of CM waveforms and Wave I or compound action potentials (CAPs) recorded at the concha were greater than those recorded at the mastoid but slightly lower than those recorded at the ear canal. Wave V amplitudes recorded at the concha were greater than those recorded at the ear canal but lower than those recorded at the mastoid. There was not a significant difference between the amplitudes recorded at the concha and at the ear canal. For CM and Wave I or CAP, the latency recorded at the concha was longer than at the canal but shorter than at the mastoid; for Wave V, the reverse was true. However, these differences were not statistically significant and may be due to the distance to response generators. Aside from the advantages that the regular ECoG has over otoacoustic emission (OAE) testing, the concha electrode was also easier and safer to place and may be suitable for children, newborn screening, participants with canal conditions, and remote clinics which could have concerns with the availability and cost of a canal electrode. Using concha electrodes, we also experienced fewer postauricular artifacts than when using a mastoid electrode.
Quality of Life in adults who stutter
Although persistent developmental stuttering is known to affect daily living, just how great the impact is remains unclear. Furthermore, little is known about the underlying mechanisms which lead to a diminished quality of life (QoL). The primary objective of this study is to explore to what extent QoL is impaired in adults who stutter (AWS). In addition, this study aims to identify determinants of QoL in AWS by testing relationships between stuttering severity, coping, functioning and QoL and by testing for differences in variable scores between two AWS subgroups: receiving therapy versus not receiving therapy. A total of 91 AWS filled in several questionnaires to assess their stuttering severity, daily functioning, coping style and QoL. The QoL instruments used were the Health Utility Index 3 (HUI3) and the EuroQoL EQ-5D and EQ-VAS. The results indicated that moderate to severe stuttering has a negative impact on overall quality of life; HUI3 derived QoL values varied from .91 (for mild stuttering) to .73 (for severe stuttering). The domains of functioning that were predominantly affected were the individual’s speech, emotion, cognition and pain as measured by the HUI3 and daily activities and anxiety/depression as measured by the EQ-5D. AWS in the therapy group rated their stuttering as more severe and recorded more problems on the HUI3 speech domain than AWS in the non-therapy group. The EQ-VAS was the only instrument that showed a significant difference in overall QoL between groups. Finally, it was found that the relationship between stuttering severity and QoL was influenced by the individual’s coping style (emotion-oriented and task-oriented). These findings highlight the need for further research into stuttering in relation to QoL, and for a broader perspective on the diagnosis and treatment of stuttering, which would take into consideration quality of life and its determinants.
from the Journal of Communication Disorders
Neural correlates of rhyming vs. lexical and semantic fluency
Rhyming words, as in songs or poems, is a universal feature of human language across all ages. In the present fMRI study a novel overt rhyming task was applied to determine the neural correlates of rhyme production.
Fifteen right-handed healthy male volunteers participated in this verbal fluency study. Participants were instructed to overtly articulate as many words as possible either to a given initial letter (LVF) or to a semantic category (SVF). During the rhyming verbal fluency task (RVF), participants had to generate words that rhymed with pseudoword stimuli. On-line overt verbal responses were audiotaped in order to correct the imaging results for the number of generated words.
Fewer words were generated in the rhyming compared to both the lexical and the semantic condition. On a neural level, all language tasks activated a language network encompassing the left inferior frontal gyrus, the middle and superior temporal gyri as well as the contralateral right cerebellum. Rhyming verbal fluency compared to both, lexical and semantic verbal fluency, demonstrated significantly stronger activation of left inferior parietal region.
Generating novel rhyme words seems to be mainly mediated by the left inferior parietal lobe, a region previously found to be associated with meta-phonological as well as sub-lexical linguistic processes.
from Brain Research
Language Lateralization in Individuals with Callosal Agenesis: An fMRI Study.
Since the seminal work of Broca in 1861, it is well established that language is essentially processed in the left hemisphere. However, the origin of hemispheric specialization remains controversial. Some authors posit that language lateralization is genetically determined, while others have suggested that hemispheric specialization develops with age. Tenants of the latter view have further suggested that the adult pattern of left hemispheric specialization is achieved by means of callosal inhibition of homologous speech areas in the right hemisphere during ontogeny. According to this hypothesis, one would expect language to develop bilaterally in the acallosal brain. A recent functional magnetic resonance imaging (fMRI) study in one patient with agenesis of the corpus callosum suggests that this might indeed be the case (Riecker et al., 2007). However, given the large anatomic and functional variability in the population of subjects with agenesis of the corpus callosum, this finding needs to be more extensively replicated. In the present study, we explored language lateralization in six individuals with agenesis of the corpus callosum using an fMRI protocol which included a syntactic decision task and a sub-vocal verbal fluency task. Two neurologically-intact control groups, one comparable to the acallosals in terms of IQ, age and education (n= 6) and one group with a high IQ (n = 5), performed the same tasks. No differences were found between language lateralization of the subjects with agenesis of the corpus callosum and the control groups in the receptive speech task. However, for expressive speech, the groups tended to differ with respect to frontal activations, with the acallosal participants showing a more bilateral pattern of activation than the High-IQ participants only. No differences were found for temporal regions. Overall, these results indicate that the corpus callosum is not essential for the establishment of lateralized language functions
from Neuropsychologia
Tinnitus Suppression by Low-Rate Electric Stimulation and Its Electrophysiological Mechanisms
Tinnitus is a phantom sensation of sound in the absence of external stimulation. However, external stimulation, particularly electric stimulation via a cochlear implant, has been shown to suppress tinnitus. Different from traditional methods of delivering speech sounds or high-rate (>2,000 Hz) stimulation, the present study found a unique unilaterally-deafened cochlear implant subject whose tinnitus was completely suppressed by a low-rate (<100 Hz) stimulus, delivered at a level softer than tinnitus to the apical part of the cochlea. Taking advantage of this novel finding, the present study compared both event-related and spontaneous cortical activities in the same subject between the tinnitus-present and tinnitus-suppressed states. Compared with the results obtained in the tinnitus-present state, the low-rate stimulus reduced cortical N100 potentials while increasing the spontaneous alpha power in the auditory cortex. These results are consistent with previous neurophysiological studies employing subjects with and without tinnitus and shed light on both tinnitus mechanism and treatment.
from Hearing Research
The agreement of caregivers’ initial identification of children’s developmental problems with the professional assessment in Taiwan
Children’s developmental problems vary, with some easier to identify than others. The accuracy of caregivers’ initial identification of children’s developmental problems is important in the timely treatment of those problems by medical professionals. In this study, we investigated the degree to which caregivers’ initial identification of children’s developmental problems matched the clinical assessment by a team of qualified professionals in a developmental assessment unit of a medical center in Taiwan. The practitioners included a pediatric neurologist, a psychiatrist, a psychologist, an occupational therapist, a physical therapist, and two speech therapists. Caregivers of 943 children (age range: 2–80 months; mean: 37.7 months) who visited the unit for a suspected developmental problem were interviewed about the chief problem that led to the caregivers bringing their children to the unit. The results showed high agreement in the global and the motor domains between the caregivers and the professionals, and low agreement in the cognitive and the speech/language domains. The agreement was significantly related to the caregivers’ native origin and socioeconomic status index (SSI). Caregivers with a foreign origin (immigrant mothers) and low SSI were more likely to misidentify their children’s problems. It is recommended that pediatric practitioners offer continuing education to caregivers, especially in the domains of cognitive and speech/language development.
The privileged status of locality in consonant harmony
While the vast majority of linguistic processes apply locally, consonant harmony appears to be an exception. In this phonological process, consonants share the same value of a phonological feature, such as secondary place of articulation. In sibilant harmony, [s] and [∫] (‘sh’) alternate such that if a word contains the sound [∫], all [s] sounds become [∫]. This can apply locally as a first-order or non-locally as a second-order pattern. In the first-order case, no consonants intervene between the two sibilants (e.g., [pisasu], [pi∫a∫u]). In second-order case, a consonant may intervene (e.g., [sipasu], [∫ipa∫u]). The fact that there are languages that allow second-order non-local agreement of consonant features has led some to question whether locality constraints apply to consonant harmony. This paper presents the results from two artificial grammar learning experiments that demonstrate the privileged role of locality constraints, even in patterns that allow second-order non-local interactions. In Experiment 1, we show that learners do not extend first-order non-local relationships in consonant harmony to second-order non-local relationships. In Experiment 2, we show that learners will extend a consonant harmony pattern with second-order long distance relationships to a consonant harmony with first-order long distance relationships. Because second-order non-local application implies first-order non-local application, but first-order non-local application does not imply second-order non-local application, we establish that local constraints are privileged even in consonant harmony.
from the Journal of Memory and Language
The probabilistic analysis of language acquisition: Theoretical, computational, and experimental analysis
There is much debate over the degree to which language learning is governed by innate language-specific biases, or acquired through cognition-general principles. Here we examine the probabilistic language acquisition hypothesis on three levels: We outline a novel theoretical result showing that it is possible to learn the exact generative model underlying a wide class of languages, purely from observing samples of the language. We then describe a recently proposed practical framework, which quantifies natural language learnability, allowing specific learnability predictions to be made for the first time. In previous work, this framework was used to make learnability predictions for a wide variety of linguistic constructions, for which learnability has been much debated. Here, we present a new experiment which tests these learnability predictions. We find that our experimental results support the possibility that these linguistic constructions are acquired probabilistically from cognition-general principles.
from Cognition
Maximum Phonation Time in Healthy Older Adults
Conclusions
MPTs were longer in this group of older adults than previously reported and did not vary significantly with age or gender. Additionally, across a single short sampling session, measurements were relatively stable across three trials of MPTs.
from the Journal of Voice
Substyles of Belting: Phonatory and Resonatory Characteristics
Belting has been described as speechlike, yell-like, or shouting voice production commonly used in contemporary commercial music genres and substantially differing from the esthetic of the Western classical voice tradition. This investigation attempts to describe phonation and resonance characteristics of different substyles of belting (heavy, brassy, ringy, nasal, and speechlike) and the classical style. A professional singer and voice teacher, skilled in these genres, served as the single subject. The recorded material was found representative according to a classification test performed by an expert panel. Subglottal pressure was measured as the oral pressure during the occlusion for the consonant /p/. The voice source and formant frequencies were analyzed by inverse filtering the audio signal. The subglottal pressure and measured flow glottogram parameters differed clearly between the styles heavy and classical assuming opposite extremes in most parameters. The formant frequencies, by contrast, showed fewer less systematic differences between the substyles but were clearly separated from the classical style with regard to the first formant. Thus, the differences between the belting substyles mainly concerned the voice source.
from the Journal of Voice
The Prevalence of Dysphonia, Its Association With Immunomediated Diseases And Correlation With Biochemical Markers
Conclusions
Systemic immunomediated diseases may associate voice disorders. Patients with SLE are those who develop these disorders more frequently. The biochemical parameters most affected during a crisis are VSG and anti-DNA antibodies.
from the Journal of Voice
The Vocal Clarity of Female Speech-Language Pathology Students: An Exploratory Study
Conclusions
The graduating student SLPs did not produce perceptually clearer voices than the beginning student SLPs. The students’ performance voices were not perceptually clearer than their habitual voices. Perceptually clear voice was associated with significantly higher HNR (dB) and lower jitter and shimmer, suggesting that acoustic noise and perturbation contribute to perceptual judgments of vocal clarity.
from the Journal of Voice
Vocal Warm-Up Practices and Perceptions in Vocalists: A Pilot Survey
Fifty-four percent of participants reported always using vocal warm-up before singing. Twenty-two percent of the participants used vocal cool down. The most preferred warm-up duration was of 5–10 minutes in duration. Despite using vocal warm-up, 26% of the participants reported experiencing voice problems. Females tended to use vocal warm-up more frequently than males. Females also tended to use longer warm-up sessions than males. Education of the participants did not appear to have any noticeable effect on the vocal warm-up practices. The most commonly used singing warm-up exercises were ascending/descending five-note scales, ascending/descending octave scales, legato arpeggios, and glissandi.
from the Journal of Voice
