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At least 1,225 records · Page 68Linked to original sources
PubMed2005

Frequency dynamics shift of vestibular evoked myogenic potentials in patients with endolymphatic hydrops.

OBJECTIVE: To measure the frequency dynamics of the vestibular evoked myogenic potential in patients with endolymphatic hydrops. STUDY DESIGN: A prospective study. SETTING: A university hospital. SUBJECTS: The endolymphatic hydrops group consisted of 28 affected ears of patients with definite unilateral Ménière's disease and a control group of 36 ears of 20 healthy volunteers. INTERVENTIONS: Vestibular evoked myogenic potentials generated by tone bursts at 250, 500, 700, 1,000, 1,500, 2,000, and 4,000 Hz were measured in both groups. Vestibular evoked myogenic potentials were also measured after furosemide administration in six patients in the endolymphatic hydrops group. MAIN OUTCOME MEASURE: The frequency sensitivity of vestibular evoked myogenic potential, as evaluated by p13-n23 normalized amplitude. RESULTS: Peak amplitudes were noted at 500 Hz in the control group and at 1,000 Hz in the endolymphatic hydrops group. After furosemide loading, peak amplitude shifted to a lower frequency in four of six ears. CONCLUSION: The peak amplitude of vestibular evoked myogenic potentials in the endolymphatic hydrops group was at a higher frequency than in the control group. The frequency of the saccule (nu) should be proportional to radical(tau/sigma), where tau is the tension of membrane and sigma is its density. We advocate the hypothesis that the shift in frequency dynamics of vestibular evoked myogenic potential in patients with endolymphatic hydrops originates from the morphologic features of the saccule, analogous to an expanded balloon.

Acoustic Stimulation↗
PubMed2006

Digital spectral analysis of the drill-bone acoustic interface during temporal bone dissection: a qualitative cadaveric pilot study.

HYPOTHESIS: To qualitatively assess the different acoustic signatures of an otologic drill burr-bone interface during temporal bone dissection on full thickness calvarial and thin tegmen bone. BACKGROUND: An appreciable change in the sound generated by drilling occurs with progressive thinning of the bone during temporal bone dissection. To date, descriptions of this phenomenon are limited to a handful of subjective characterizations. Using digital power spectral analysis, interpretation of complex functions of time such as acoustic signals can be interpreted. METHODS: Acoustic data recorded from five cadaveric temporal bone dissections were studied using digital spectral analysis. RESULTS: The energy bandwidth concentration was between 5.0 and 7.9 kHz for full thickness bone using the cutting burr. Thin tegmen bone bandwidth concentration was lower, between 3.7 and 7.4 kHz and 3.9 and 6.0 kHz, using cutting and diamond burrs, respectively. Harmonic frequencies for thin tegmen bone-burr signals were 630 Hz. CONCLUSION: There is a consistent, reproducible qualitative difference in the spectral domain of the acoustic signature from the drill burr-bone interface between thick calvarial bone and thin tegmen bone caused by a higher harmonic peak interval and lower energy bandwidth concentration in the thinned tegmen bone-burr interface signal thus concentrating the acoustic signal within a more optimal frequency range for human perception. These results allow for a better understanding of the perceived change in sound with progressive thinning of bone with drilling. In addition, these data may allow the development of more realistic acoustic interfaces in virtual reality temporal bone dissection simulators.

Acoustics↗
PubMed2005

A new instrument for intraoperative assessment of individual vocal folds.

OBJECTIVES: Intraoperative assessment of vocal fold vibration during phonomicrosurgery performed under general anesthesia may enhance surgical decision-making. We therefore developed and bench-tested a new device we refer to as the aerodynamic vocal fold driver (AVFD). MATERIALS AND METHODS: The AVFD comprises a hand-held probe that uses airflow to drive individual vocal folds into phonatory-like vibration. This permits stroboscopic visualization of mucosal waves with simultaneous control of subglottal air pressure. In initial experiments to validate the technique, AVFD driven phonation and conventional whole-larynx phonation were compared using excised canine larynges (n = 14). RESULTS: Single vocal fold phonation using the AVFD and whole larynx phonation yielded similar, positive correlations between subglottal pressure and both amplitude and frequency of vibration. Experiments simulating vocal fold scar-related mucosal stiffening by subepithelial injection of fixative showed the expected elevation of phonation threshold pressures as measured with the AVFD. Likewise, unilateral tissue compression injury disrupted vocal fold vibration, and the AVFD was useful for quantifying improvement in the damaged vocal fold after repair with injection of cross-linked hyaluronic acid gel. CONCLUSIONS: These results show that this new instrument has the potential to provide novel and useful information for laryngeal experimentation and to improve phonosurgery.

Air↗
PubMed2006

Estimating subglottal pressure using incomplete airflow interruption.

OBJECTIVE/HYPOTHESIS: Subglottal pressure (SGP) measurements are often used to assess laryngeal function; however, current methods to measure SGP are invasive or do not estimate SGP during phonation. The purpose of this study was to devise a noninvasive technique to estimate SGP without interrupting phonation. STUDY DESIGN: This was a methodologic study designed to calculate the SGP of a human subject. METHODS: A new technique to estimate SGP was developed in which subject airflow was partially interrupted by introducing two different impedances (pneumatic resistors) through a balloon valve controlled mouthpiece. The changes in airflow across varying impedances were used to estimate SGP in human subjects based on the predictable relationships between SGP, impedance, and airflow measurements. The technique was used to assess eight human subjects (age 19-30) phonating at intensities of 65, 72, and 80 dB. RESULTS: The estimated SGP from the human subjects fell within a range (5.52-8.91 cm H20) that was consistent with previous studies. As other studies have found, SGP estimations significantly increased as subjects phonated at greater intensities (P < .01). Intrasubject standard deviations compared favorably with those from previous studies of complete airflow interruption, suggesting satisfactory reliability. The technique was validated using a mechanical "pseudolung" device (r = 0.9982). CONCLUSIONS: Incomplete airflow interruption offers the potential for useful clinical application to assess the severity of vocal pathology by estimating SGP during continuous phonation.

Adult↗
PubMed2006

Acoustic analysis of snoring sounds by a multidimensional voice program.

OBJECTIVES: This prospective study aimed to determine whether the acoustic characteristics of snoring sounds differed between simple snorers and patients with obstructive sleep apnea syndrome (OSAS) by using a multidimensional voice program (MDVP) that analyzes various aspects of voice. METHODS: Fifty-eight patients (48 men, 10 women) with a history of snoring were included in the study. All patients underwent conventional polysomnography (PSG). Twelve subjects were diagnosed as simple snorers and 46 subjects were diagnosed with OSAS. The mean body mass index (BMI) of simple snorers was 24.7 kg/m and that of patients with OSAS was 25.8 kg/m. Natural overnight snoring was recorded from each subject while they slept during PSG. Using the multiple token protocols of MDVP, 30 snores from each subject were analyzed automatically. For data analysis, four markers were used: peak frequency, soft phonation index (SPI), noise to harmonics ratio (NHR), and power ratio. RESULTS: The Mann-Whitney U test revealed significant differences between the SPI, NHR, and power ratio of simple snorers and patients with OSAS. Simple snorers had a high SPI value. OSAS-related snorers demonstrated a high NHR and low power ratio. CONCLUSIONS: MDVP can be used for snoring sound analysis as a noninvasive examination of sleep-related breathing disorders for differential diagnosis. However, a suitable option that is rapid and has an easy-to-use interface would be more advantageous for analyzing snoring sounds.

Diagnosis, Differential↗
PubMed2006

Development and validation of the vocal tremor scoring system.

BACKGROUND: Essential tremor (ET) occurs in approximately 4% of the population, and 25% of patients with ET have vocal tract involvement referred to as essential tremor of voice (ETV). Treatment of vocal tremor has a variable success rate most likely as a result of inaccurate identification of the affected area(s). A vocal tremor assessment system was developed to standardize the evaluation and scaling of vocal tremor. Applying this system clinically can help determine who will benefit most from botulinum toxin injection treatment. The Vocal Tremor Scoring System (VTSS) can also be used as a tool to determine treatment efficiency for all treatment modalities of ETV, including surgery, medications, and implantable devices. STUDY DESIGN: The authors studied instrument development and validation. METHODS: A clinical consensus conference was conducted to develop an assessment tool for standardized rating of vocal tremor location and severity. The assessment tool was then tested for reliability using video-perceptual analysis. Once validated, the assessment tool was applied to 10 examinations of patients with vocal tremor who had been treated with botulinum toxin A (BtxA) injections of the thyroarytenoid muscle(s) to determine the ability of the scoring instrument to predict treatment outcome. RESULTS: : The VTSS is based on severity scores for different anatomic sites within the vocal tract. The assessment areas of the VTSS are the palate, base of tongue, pharyngeal walls, larynx, supraglottis, and true vocal cords. Statistical analysis of the video-perceptual analysis results showed that the anatomic sites with the best interrater agreement were the true vocal folds, palate, base of tongue, and supraglottis. Overall, the VTSS demonstrated a level of interrater reliability of at least 0.914 at all sites. Intrarater reliability was excellent. The consensus group also analyzed 10 standardized examinations and the scores from both reviewer groups were then compared and found to have a reliability of at least 0.6 at each site. Pretreatment VTSS scores of 10 patients with ETV who underwent BtxA therapy were then compared with treatment response. The VTSS predicted the favorable treatment outcome 100% of the time when the score given to the true vocal folds was equal or greater to the mean of the scores given to the other sites. CONCLUSION: The VTSS represents the first standardized system for rating anatomic site(s) and severity of vocal tremor. This tool will allow improved communication between otolaryngologists, facilitate research in vocal tremor treatments, and establish a descriptive system for assessing vocal tremor. Using this assessment tool for patients with vocal tremor increases optimal patient selection and success rate for intralaryngeal botulinum toxin treatment.

Aged↗
PubMed2004

The impact of hormonal fluctuations on female vocal folds.

PURPOSE OF REVIEW: Sex hormone fluctuations were shown to affect female vocal folds and laryngeal function. Laryngeal changes are evident throughout the span of life, starting at puberty with the arousal of the hormonal system, fluctuating systematically during the reproductive years with the menstrual cycle, and then changing again with the decline of hormonal activity at menopause. This paper reviews recent developments in this field. RECENT FINDINGS: Early studies that explored this relation were based merely on subjective impressions of voice quality, recent studies have used more objective tools for examining this relation, including histologic observations, stroboscope, electroglottography (EGG), and computerized acoustic analyses. In these studies, the larynx was shown to be a hormonal target organ and, as such, sex hormones affect its morphology, histology, and function, similar to their effect on the genitals and other organs. SUMMARY: Examining the relation between sex hormones and the larynx could assist in understanding the mechanisms of voice production, and it could provide the clinician with supplemental diagnostic information on different medical conditions.

Adolescent↗
PubMed2004

Neural correlates of song complexity in Bengalese finch high vocal center.

Auditory neurons in the songbird forebrain nucleus high vocal center HVC) show high selectivity to the temporal structure of bird's own song but the relationship between the degree of song complexity and neural selectivity is not known. We investigated the song temporal selectivity of HVC neurons by multi-unit recordings in seven male Bengalese finches with different song complexity. Results showed that HVC multi-units of the individuals with more complex songs responded strongly to each of the self-generated song elements but were relatively insensitive to the element order, while those with stereotyped songs responded only to the song elements ordered exactly as in the self-produced songs. Data suggest that the individually learned song syntax correlates with individualized temporal combination selectivity in HVC neurons.

Acoustic Stimulation↗
PubMed2006

Contact-call driven and tone-driven zenk expression in the nucleus ovoidalis of the budgerigar (Melopsittacus undulatus).

The effectiveness of species-typical contact calls and a 3-kHz pure tone to induce zenk gene protein expression in the primary thalamic auditory relay nucleus ovoidalis was compared in budgerigars (Melopsittacus undulatus), a parrot species capable of lifelong vocal learning. Ovoidalis consists of a core which projects topographically to field L of the telencephalon and a ventromedial shell containing many calcitonin-gene-related peptide neurons that project throughout field L as well as to an adjacent field receiving visual input. Tone-induced and call-induced zenk expression in the ovoidalis core were similar; however, call-induced zenk expression in ventromedial ovoidalis shell was significantly greater than tone-induced expression. These results support the idea that the ovoidalis shell may contain neurons specialized to process complex sounds including species-typical communication sounds.

Acoustic Stimulation↗
PubMed2006

Specificity of experience-dependent pitch representation in the brainstem.

Crosslanguage comparisons of brainstem-evoked potentials have revealed experience-dependent plasticity in pitch representation for curvilinear f0 contours representative of Mandarin tones. To assess the tolerance limits of this experience-dependent selectivity, we evaluated cross-linguistically (Chinese, English) the pitch strength and tracking accuracy of linear rising and falling f0 ramps representative of Mandarin tones 2 and 4. No crosslanguage differences in pitch strength or accuracy were observed for either tone, indicating that stimuli with linear rising/falling ramps elicit homogeneous pitch representations at the level of the brainstem regardless of language experience. We conclude that pitch extraction at the brainstem level is critically dependent on specific dimensions of pitch contours that native speakers have been exposed to in natural speech contexts.

Acoustic Stimulation↗
PubMed2004

Pacific and Atlantic herring produce burst pulse sounds.

The commercial importance of Pacific and Atlantic herring (Clupea pallasii and Clupea harengus) has ensured that much of their biology has received attention. However, their sound production remains poorly studied. We describe the sounds made by captive wild-caught herring. Pacific herring produce distinctive bursts of pulses, termed Fast Repetitive Tick (FRT) sounds. These trains of broadband pulses (1.7-22 kHz) lasted between 0.6 s and 7.6 s. Most were produced at night; feeding regime did not affect their frequency, and fish produced FRT sounds without direct access to the air. Digestive gas or gulped air transfer to the swim bladder, therefore, do not appear to be responsible for FRT sound generation. Atlantic herring also produce FRT sounds, and video analysis showed an association with bubble expulsion from the anal duct region (i.e. from the gut or swim bladder). To the best of the authors' knowledge, sound production by such means has not previously been described. The function(s) of these sounds are unknown, but as the per capita rates of sound production by fish at higher densities were greater, social mediation appears likely. These sounds may have consequences for our understanding of herring behaviour and the effects of noise pollution.

Anal Canal↗
PubMed2004

Duet singing and repertoire use in threat signalling of individuals and pairs.

Song-type switching rate and song matching have been shown to function as territorial signals in male solo song but, to our knowledge, seem not to have been previously studied in a duetting species. We studied the plain wren (Thryothorus modestus zeledoni), to test whether duets signalled threat through song-switching rates, or through phrase type or duet type matching. Increases in the rate of song switching appear to function as an anti-habituation device rather than as a specific signal of threat. Fitting with previous results that same-sex individuals share phrase types, but pairs do not share duet types, both males and females used duets to phrase type match to playback. Pairs, however, did not duet type match in response to playback, and this suggests that within the cooperative territory defence of the duet, each sex is targeting its aggression at same-sex competitors.

Acoustic Stimulation↗
PubMed2004

Sex-linked inheritance of hearing and song in the Belgian Waterslager canary.

Belgian Waterslager canaries have less sensitive hearing at high frequencies and produce songs with more energy at low frequencies than wild-type canaries. A backcross pedigree between Belgian Waterslager canaries and a domestic strain with wild-type song revealed inheritance patterns consistent with a factor of major effect located on the Z sex chromosome affecting both poor high-frequency hearing at 4 kHz and the relative energy in the spectra of the learned songs of males. Hearing thresholds at 4 kHz were significant predictors of the relative amount of song energy at 4 kHz for individual males. One hypothesis for the mechanistic basis of this correlation between hearing and song abnormalities is that a reduction in the ability to hear higher-frequency songs biases males towards learning lower-frequency songs.

Animals↗
PubMed2004

Beaked whales echolocate on prey.

Beaked whales (Cetacea: Ziphiidea) of the genera Ziphius and Mesoplodon are so difficult to study that they are mostly known from strandings. How these elusive toothed whales use and react to sound is of concern because they mass strand during naval sonar exercises. A new non-invasive acoustic ording tag was attached to four beaked whales(two Mesoplodon densirostris and two Ziphius cavirostris) and recorded high-frequency clicks during deep dives. The tagged whales only clicked at depths below 200 m, down to a maximum depth of 1267 m. Both species produced a large number of short, directional, ultrasonic clicks with significant energy below 20 kHz. The tags recorded echoes from prey items; to our knowledge, a first for any animal echolocating in the wild. As far as we are aware, these echoes provide the first direct evidence on how free-ranging toothed whales use echolocation in foraging. The strength of these echoes suggests that the source level of Mesoplodon clicks is in the range of 200-220 dB re 1 microPa at 1 m. This paper presents conclusive data on the normal vocalizations of these beaked whale species, which may enable acoustic monitoring to mitigate exposure to sounds intense enough to harm them.

Animals↗
PubMed2004

Distress calls may honestly signal bird quality to predators.

In predator-prey interactions, both interactors may benefit from sharing information about prey vulnerability. We examined the relationship between calls used to discourage close predators (distress calls) and the health condition of the caller to test whether these signals are reliable indicators of prey quality. The structure of calls from captured lesser short-toed larks Calandrella rufescens was related to their body condition and T-cell-mediated immunocompetence. Birds in better nutritional and immunological condition utter harsher calls (i.e. they spread the call energy over a wider range of frequency) than birds in poorer conditions. Hence, the harshness of distress calls seems honestly to signal the health status of prey and thus their ability to escape, on which the predator might base its optimal foraging choice. Previous studies have investigated the honesty of songs that have evolved via sexual selection, but this is the first study, to our knowledge, the demonstrates a relationship between individual quality and a vocalization primarily shaped by natural selection.

Analysis of Variance↗
PubMed2006

The influence of social affiliation on individual vocal signatures of northern resident killer whales (Orcinus orca).

Northern resident killer whales (Orcinus orca) live in highly stable groups and use group-specific vocal signals, but individual variation in calls has not been described previously. A towed beam-forming array was used to ascribe stereotyped pulsed calls with two independently modulated frequency contours to visually identified individual killer whales in Johnstone Strait, British Columbia. Overall, call similarity determined using neural networks differed significantly between different affiliation levels for both frequency components of all the call types analysed. This method distinguished calls from individuals within the same matriline better than different calls produced by a single individual and better than by chance. The calls of individuals from different matrilines were more distinctive than those within the same matriline, confirming previous studies based on group recordings. These results show that frequency contours of stereotyped calls differ among the individuals that are constantly associated with each other and use group-specific vocalizations, though across-group differences were substantially more pronounced.

Animals↗
PubMed2006

Killer whales are capable of vocal learning.

The production learning of vocalizations by manipulation of the sound production organs to alter the physical structure of sound has been demonstrated in only a few mammals. In this natural experiment, we document the vocal behaviour of two juvenile killer whales, Orcinus orca, separated from their natal pods, which are the only cases of dispersal seen during the three decades of observation of their populations. We find mimicry of California sea lion (Zalophus californianus) barks, demonstrating the vocal production learning ability for one of the calves. We also find differences in call usage (compared to the natal pod) that may reflect the absence of a repertoire model from tutors or some unknown effect related to isolation or context.

Animals↗
PubMed2003

Mother-lamb acoustic recognition in sheep: a frequency coding.

Ewes of the domestic sheep ( Ovis aries ) display selective maternal investment by restricting care to their own offspring and rejecting alien young. This trait relies on individual recognition processes between ewes and lambs. Whereas identification at the udder is only olfactory, distance recognition is performed through visual and acoustic cues. We studied the effectiveness and modalities of mutual acoustic recognition between ewes and lambs by spectrographic analysis of their vocal signatures and by playbacks of modified calls in the field. Our results show that ewes and their lambs can recognize each other based solely on their calls. The coding of identity within the vocal signatures, previously unknown in sheep, is similar in lamb and ewe: it uses the mean frequency and the spectral energy distribution of the call, namely the timbre of the call. These results point out a simple signature system in sheep that uses only the frequency domain. This engenders a signal with low information content, as opposed to some highly social birds and mammal species that may integrate information both in the temporal and spectral domains. The simplicity of this system is linked to the roles played by vision and olfaction that corroborate the information brought by the vocal signature.

Animals↗