Vocal fold nodules: A disorder of phonation organs or auditory feedback?

OBJECTIVE: Increasing evidence supports that auditory feedback of one's own voice closely relates to real-time adjustments of vocal control. Previous studies highlighted that the low-frequency modulations of below 3 Hz (LFM) embedded in vocal fundamental frequency (F0) showed a reflex-like response to altered auditory inputs. However, the auditory feedback control of different vocal disorders remains unclear. DESIGN: A cross-sectional, case-controlled study. SETTING: A tertiary medical centre. PARTICIPANTS: Sustained vocalisations of vowel/a/ from adult healthy controls and patients with vocal fold nodules, vocal fold polyps and vocal fold cysts, respectively. The vocalisations were made at a comfortable pitch and at the intensity of 70 ~ 80 dBC under the following four auditory conditions: natural hearing, 90-dBC speech noise, 10-dBC enhanced feedback of self-produced voice and both the noise and voice feedback. MAIN OUTCOME MEASURES: Power spectral analysis of F0 contour of sustained vowel. RESULTS: Patients with vocal fold nodules presented with different audio-vocal feedback behaviour and audio-vocal response to speech noise from the other two vocal pathologies of vocal fold polyp and vocal fold cyst as well as the healthy controls (P < .001, one-way ANOVA). CONCLUSION: The vocal fold nodules may be not only a vocal fold disease but also a disease caused by abnormal audio-vocal feedback. Moreover, the distinct audio-vocal feedback of vocal fold nodules could be revealed by power spectral analysis of vocal fundamental frequencies. Although further investigations are necessary, adjustments of audio-vocal feedback behaviour may provide a new insight and benefit to the treatment of vocal fold nodules in the future.

Snoring sound energy as a potential biomarker for disease severity and surgical response in childhood obstructive sleep apnoea: A pilot study.

OBJECTIVE: To investigate the relationship between baseline snoring sound energy (SSE) and disease severity, changes in SSE after adenotonsillectomy, and the predictors of surgical success in children with obstructive sleep apnoea (OSA). DESIGN: Prospective cohort study. SETTING: Tertiary referral medical centre. PARTICIPANTS: Thirty-two children with OSA whose apnoea-hypopnoea index ≥5 or apnoea-hypopnoea index ≥1.5 with OSA comorbidities were recruited. Patients with complicated OSA were excluded. All participants underwent snoring sound analysis, polysomnography, and adenotonsillectomy. MAIN OUTCOME MEASURES: Snoring sound energy and apnoea-hypopnoea index were assessed at baseline and 6 months after adenotonsillectomy. Surgical success was defined as a postoperative apnoea-hypopnoea index <1.5. RESULTS: The median age, body mass index, and apnoea-hypopnoea index was 9 years, 19.0 kg/m2 , and 13.2 events/h, respectively. Multivariate logistic regression showed that a baseline tonsil size of IV (odds ratio 15.7 [95% CI: 1.5-166.3]) and SSE of 801-1000 Hz > 21.9 dB (odds ratio 32.3 [95% CI: 2.6-396.6]) were significantly related to severe OSA. Following adenotonsillectomy, apnoea-hypopnoea index decreased significantly (P < 0.001). SSE of 41-200 Hz, 201-400 Hz and 801-1000 Hz also decreased significantly (P = 0.04, 0.01 and 0.006, respectively). Baseline SSE of 801-1000 Hz < 8.5 dB significantly predicted surgical success (odds ratio 11.0 [95% CI: 1.4-85.2]). CONCLUSIONS: Our findings suggest the potential utility of SSE of 801-1000 Hz to screen for severe OSA, predict surgical success and assess therapeutic outcomes. Specific baseline SSE may represent a potential biomarker for childhood OSA.

Saccadic entropy of head impulses in acute unilateral vestibular loss.

BACKGROUND/PURPOSE: To evaluate the complexity of vestibular-ocular reflex (VOR) in patients with acute unilateral vestibular loss (AUVL) via entropy analysis of head impulses. METHODS: Horizontal head impulse test (HIT) with high-velocity alternating directions was used to evaluate 12 participants with AUVL and 16 healthy volunteers. Wireless electro-oculography and electronic gyrometry were used to acquire eye positional signals and head velocity signals. The eye velocity signals were then obtained through differentiation, band-pass filtering. The approximate entropy of eye velocity to head velocity (RApEn) was used to evaluate chaos property. VOR gain, gain asymmetry ratio, and RApEn asymmetry ratio were also used to compare the groups. RESULTS: For the lesion-side HIT of the patient group, the mean VOR gain was significantly lower and the mean RApEn was significantly greater compared with both nonlesion-side HIT and healthy controls (p < 0.01, one-way analysis of variance). Both the RApEn asymmetry ratio and gain asymmetry ratio of the AUVL group were significantly greater compared with those of the control group (p < 0.05, independent sample t test). CONCLUSION: Entropy and gain analysis of HIT using wireless electro-oculography system could be used to detect the VOR dysfunctions of AUVL and may become effective methods for evaluating vestibular disorders.

Unstable sleep and higher sympathetic activity during late-sleep periods of rats: implication for late-sleep-related higher cardiovascular events.

We proposed that the higher incidence of sleep fragmentation, sympathovagal imbalance and baroreceptor reflex impairment during quiet sleep may play a critical role in late-sleep-related cardiovascular events. Polysomnographic recording was performed through wireless transmission using freely moving Wistar-Kyoto rats over 24 h. The low-frequency power of arterial pressure variability was quantified to provide an index of vascular sympathetic activity. Spontaneous baroreflex sensitivity was assessed by slope of arterial pressure-RR linear regression. As compared with early-light period (Zeitgeber time 0-6 h), rats during the late-light period (Zeitgeber time 6-12 h) showed lower accumulated quiet sleep time and higher paradoxical sleep time; furthermore, during quiet sleep, the rats showed a lower δ% of electroencephalogram, more incidents of interruptions, higher σ% and higher ß% of electroencephalogram, raised low-frequency power of arterial pressure variability value and lower baroreflex sensitivity parameters. During the light period, low-frequency power of arterial pressure variability during quiet sleep had a negative correlation with accumulated quiet sleep time and δ% of electroencephalogram, while it also had a positive correlation with σ% and ß% of electroencephalogram and interruption events. However, late-sleep-related raised sympathetic activity and sleep fragmentation diminished when an α1-adrenoceptor antagonist was given to the rats. Our results suggest that the higher incidence of sleep fragmentation and sympathovagal imbalance during quiet sleep may play a critical role in late-sleep-related cardiovascular events. Such sleep fragmentation is coincident with an impairment of baroreflex sensitivity, and is mediated via α1-adernoceptors.

Cochlear dead region and word recognition of Mandarin Chinese in Taiwan.

In a tonal language, the identity of a word depends largely on the tonal identification of the contour of vocal fundamental frequency energy of which usually centers in a low frequency of less than 600 Hz. However, cochlear dead region (DR) is present mostly in the frequency range of 2000 Hz to 4000 Hz, and the effect of DR on a tonal language is worth investigating. Thirty-two native Mandarin speakers with moderate-to-severe degree of sensorineural hearing loss were included in this study. The pure-tone audiometry, speech recognition threshold (SRT) and word recognition score (WRS) were used to evaluate the degree of hearing loss and word recognition. The threshold equalizing noise (TEN) tests were used to identify the presence of DR. The results showed that most DRs were present in high frequencies. The hearing thresholds of the ears with a DR were not significantly different from those without DR. However, the WRS was significantly worse for the DR ears, especially for those whose DR included three or more audiometric frequencies. A DR caused a significantly worse word recognition for the tonal language speakers of Mandarin in Taiwan, although the DR frequency occurred in the high frequency of 2000 Hz to 4000 Hz.

Heart rate variability analysis in patients with allergic rhinitis.

BACKGROUND: Very few studies investigate the role of the autonomic nervous system in allergic rhinitis. In this study, we evaluated the autonomic nervous system in allergic rhinitis patients using heart rate variability (HRV) analysis. METHODS: Eleven patients with allergic rhinitis and 13 healthy controls, aged between 19 and 40 years old, were enrolled in the study. Diagnosis of allergic rhinitis was based on clinical history, symptoms, and positive Phadiatop test. Electrocardiographic recordings on the sitting and supine positions were obtained for HRV analysis. RESULTS: In the supine position, there were no significant statistical differences in very-low-frequency power (VLF, ≤0.04 Hz), low-frequency power (LF, 0.04-0.15 Hz), high-frequency power (HF, 0.15-0.40 Hz), and the ratio of LF to HF (LF/HF) between the patient and control groups. The mean RR intervals significantly increased, while LF% and LF/HF significantly decreased in the patient group in the sitting position. Moreover, mean RR intervals, LF, and LF/HF, which were significantly different between the two positions in the control group, did not show a significant change with the posture change in the patient group. CONCLUSION: These suggest that patients with allergic rhinitis may have poor sympathetic modulation in the sitting position. Autonomic dysfunction may therefore play a role in the pathophysiology of allergic rhinitis.

Using sleep heart rate variability to investigate the sleep quality in children with obstructive sleep apnea.

Background: Obstructive sleep apnea (OSA) is associated with impaired sleep quality and autonomic dysfunction. Adenotonsillectomy significantly improves subjective and objective sleep quality in children with OSA. However, the postoperative changes in heart rate variability (HRV) indices (indicators of cardiac autonomic function) and their importance remain inconclusive in childhood OSA. This retrospective case series aimed to investigate the association of sleep HRV indices, total OSA-18 questionnaire score (a subjective indicator of sleep quality) and polysomnographic parameters (objective indicators of sleep quality), and effects of adenotonsillectomy on HRV indices, total OSA-18 questionnaire score and polysomnographic parameters in children with OSA. Methods: Seventy-six children with OSA were included in baseline analysis, of whom 64 (84%) completed at least 3 months follow-up examinations after adenotonsillectomy and were included in outcome analysis. Associations between baseline variables, and relationships with treatment-related changes were examined. Results: Multivariable linear regression models in the baseline analysis revealed independent relationships between tonsil size and obstructive apnea-hypopnea index (OAHI), adenoidal-nasopharyngeal ratio and very low frequency (VLF) power of HRV (an indicator of sympathetic activity), and normalized low frequency power (an indicator of sympathetic activity) and OAHI. The outcome analysis showed that adenotonsillectomy significantly improved standard deviation of all normal-to-normal intervals, and high frequency power, QoL (in terms of reduced total OSA-18 questionnaire score), OAHI and hypoxemia. Using a conceptual serial multiple mediation model, % change in OSA-18 questionnaire score and % change in VLF power serially mediated the relationships between change in tonsil size and % change in OAHI. Conclusions: The improvement in OAHI after adenotonsillectomy was serially mediated by reductions in total OSA-18 questionnaire score and VLF power. These preliminary findings are novel and provide a direction for future research to investigate the effects of VLF power-guided interventions on childhood OSA.

Dietary profile of pediatric obstructive sleep apnea patients, effects of routine educational counseling, and predictors for outcomes.

Background: Dietary behavior is a main contributing yet modifiable factor to the body weight status of children and may be involved in the pathophysiology of childhood obstructive sleep apnea (OSA). This study aimed to investigate the dietary profile of pediatric OSA patients, effects of educational counseling after adenotonsillectomy, and predictor for disease resolution. Methods: This observational study included 50 pediatric OSA patients undergoing adenotonsillectomy with routine educational counseling (Group 1), 50 pediatric OSA patients undergoing adenotonsillectomy without formal educational counseling (Group 2), and 303 healthy children without OSA (Control). The three groups were matched by age. The consumption frequency of 25 food items/groups was assessed by the Short Food Frequency Questionnaire. Quality of life was evaluated by the OSA-18 questionnaire. Sleep architecture and OSA severity were measured by standard polysomnography. Between- and within-group comparisons were analyzed by non-parametric approaches and generalized estimating equations. Prediction of disease recovery was performed by multivariable logistic regression models. Results: Group 1 children consumed fruit drinks with sugar, vegetables, sweets, chocolate, rice, and noodles more frequently than Control Group children. At baseline, the distributions of sex, weight status, OSA-18 scores, and polysomnographic variables were comparable between Group 1 and Group 2. After a 12-month follow-up, Group 1 had better improvements in physical suffering, caregiver concerns, sleep architecture, and mean peripheral oxygen saturation compared to Group 2. Furthermore, Group 1 no longer had excessive consumption of fruit drinks with sugar, chocolate, and noodles; however, food consumption frequencies did not change significantly. Notably, younger age and reduced intake of butter/margarine on bread and noodles were independent predictors of cured OSA in Group 1. Conclusion: The present study preliminarily characterized an unhealthy dietary profile among pediatric OSA patients and suggested that routine educational counseling in addition to adenotonsillectomy yielded some clinical benefits. Certain items/groups of food frequencies may be associated with disease recovery and further investigations are warranted.

Adenotonsillectomy-related changes in systemic inflammation among children with obstructive sleep apnea.

BACKGROUND: Adenotonsillar hypertrophy is the most common cause of pediatric obstructive sleep apnea (OSA). Although adenotonsillectomy considerably reduces OSA and systemic inflammation, whether and how systemic inflammation influences the effects of adenotonsillectomy on OSA has yet to be determined. METHODS: This study investigated the associations between changes in anatomical variables, % changes in subjective OSA-18 questionnaire scores, % changes in 11 polysomnographic parameters, and % changes in 27 systemic inflammatory biomarkers in 74 children with OSA. RESULTS: Fifty-six (75.6%) boys and 18 (24.4%) girls with the mean age of 7.4 ± 2.2 years and apnea-hypopnea index (AHI) of 14.2 ± 15.9 events/h were included in the statistical analysis. The mean period between before and after adenotonsillectomy was 5.6 ± 2.6 months. After adenotonsillectomy, the OSA-18 score, eight of 11 polysomnographic parameters, and 20 of 27 inflammatory biomarkers significantly improved (all p < 0.005). Notably, there were significant associations between change in tonsil size and % change in AHI ( r = 0.23), change in tonsil size and % changes in interleukin-8 (IL-8) ( r = 0.34), change in tonsil size and % change in and IL-10 ( r = -0.36), % change in IL-8 and % change in C-C chemokine ligand 5 (CCL5) ( r = 0.30), and % change in CCL5 and % change in AHI ( r = 0.38) (all p < 0.005). Interestingly, % change in IL-8 and % change in CCL5 serially mediated the relationship between change in tonsil size and % change in AHI (total effect: ß = 16.672, standard error = 8.274, p = 0.048). CONCLUSION: These preliminary findings suggest that systemic inflammation is not only a complication of OSA but also that it mediates the surgical effects, which may open avenues for potential interventions to reduce tonsil size and OSA severity through the regulation of IL-8 and CCL5.

Voice low tone to high tone ratio, nasalance, and nasality ratings in connected speech of native Mandarin speakers: a pilot study.

OBJECTIVE: Voice low tone to high tone ratio (VLHR) is defined as the power ratio of a voice spectrum with a specific cut-off frequency. Previous studies have shown that there are significant correlations between VLHR and nasalance and hypernasality ratings in vowels. The correlation was investigated in this study using connected speech material. DESIGN: The Zoo Passage, the Rainbow Passage, the English Nasal Sentences, the Mandarin Nonnasal Sentences, and the Mandarin Nasal Sentences were used to acquire VLHRs, nasalance scores, and perceptual judgments of nasality. Each passage was recorded twice for averaging, and the cut-off frequencies from 200 Hz to 1200 Hz were used to survey for the presence of optimal correlations with VLHR. Participants : Ten native Mandarin speakers with an English learning history of over 8 years were enrolled. Main outcome measures : VLHRs, nasalance scores, and hypernasality ratings. RESULTS: The correlations of VLHR with nasalance (rho  =  .76, p < .001, Spearman rank correlation) and nasality ratings (rho  =  .81, p < .001) were significant using a cut-off frequency of 300 Hz for the English passages. For the Mandarin Sentences, the optimal correlations of VLHR with nasalance (rho  =  .83, p < .001) and nasality ratings (rho  =  .79, p < .001) were identified using a cut-off frequency of 500-Hz. CONCLUSION: The significant correlations of VLHR with nasalance and perceptual ratings of nasality using connected speech show that these approaches have a potential value in terms of basic and clinical application.

Comparisons of auditory brainstem response elicited by compound click-sawtooths sound and synthetic consonant-vowel /da/.

The auditory brainstem response to complex sounds (cABR) could be evoked using speech sounds such as the 40 ms synthetic consonant-vowel syllable /da/ (CV-da) that was commonly used in basic and clinical research. cABR consists of responses to formant energy as well as the energy of fundamental frequency. The co-existence of the two energy makes cABR a mixed response. We introduced a new stimulus of click-sawtooths (CSW) with similar time-lock patterns but without formant or harmonic energy. Ten young healthy volunteers were recruited and the cABRs of CV-da and CSW of their 20 ears were acquired. The response latencies, amplitudes, and frequency-domain analytic results were compared pairwisely between stimuli. The response amplitudes were significantly greater for CSW and the latencies were significantly shorter for CSW. The latency-intensity functions were also greater for CSW. For CSW, adjustments of energy component can be made without causing biased changes to the other. CSW may be used in future basic research and clinical applications.

Contributions of Forward-Focused Voice to Audio-Vocal Feedback Measured Using Nasal Accelerometry and Power Spectral Analysis of Vocal Fundamental Frequency.

PURPOSE: The spectral powers of the modulations of vocal fundamental frequency (f o) less than 3 Hz (low-frequency power, LFP) and between 3 and 8 Hz (middle-frequency power, MFP) had been established to indicate the audio-vocal feedback status and vocal efficiency of a speaker, and a resonant voice may enhance the auditory-vocal feedback. This study aims to determine whether the auditory feedback can be augmented by a forward and resonant voice and therefore contribute to the modulations of f o variability. METHOD: Vocal signals and accelerometric signals of lateral nasal cartilage were obtained from 27 healthy adults who, respectively, sustained vowels /a/ and /i/ with their habitual speaking voice and with a forward-focused voice under three auditory conditions: natural hearing (N0), high-level noise exposure (N90), and low-level noise exposure (N60). Nasal skin vibrations were measured using a nasal accelerometry to reflect voice resonance status. Vocal intensity and f o variability were also analyzed to show the auditory-vocal interactions under varied conditions of auditory feedback and voice resonance. RESULTS: In both N0 and N90 conditions, forward-focused voice showed a significantly lower LFP than the speakers' habitual voice. In addition, LFP of f o would significantly increase during natural voice production as the voice feedback was greatly masked by high-intensity noise; however, with a forward-focused voice, the noise-induced variation in LFP was significantly decreased. Under N90, MFP significantly decreased during forward-focused voice production compared with that measured during natural voice production. The stability of f o modulations was not adversely affected by N60. CONCLUSION: The results support the idea that vocalizing with a forward-focused voice enhance the auditory feedback of the speaker's own voice and, thus, reduce the variability of f o during sustained phonation, especially when vocalizing in the high noise condition.

Long-term Average Spectrum and Nasal Accelerometry in Sentences of Differing Nasality and Forward-Focused Vowel Productions Under Altered Auditory Feedback.

OBJECTIVES AND BACKGROUND: To investigate whether voice focus adjustments can alter the audio-vocal feedback and consequently modulate speech/voice motor control. Speaking with a forward-focused voice was expected to enhance audio-vocal feedback and thus decrease the variability of vocal fundamental frequency (F0). MATERIALS AND METHOD: Twenty-two healthy, untrained adults (10 males and 12 females) were requested to sustain vowel /a/ with their natural focus and a forward focus and to naturally read the nasal, oral, and mixed oral-nasal sentences in normal noise-masked auditory conditions. Meanwhile, a miniature accelerometer was externally attached on the noise to detect the nasal vibrations during vocalization. Audio recordings were made and analyzed using the long-term average spectrum (LTAS) and power spectral analysis of F0. RESULTS: Compared with naturally-focused vowel production and oral sentences, forward-focused vowel productions and nasal sentences both showed significant increases in nasal accelerometric amplitude and the spectral power within the range of 200∼300 Hz, and significantly decreased the F0 variability below 3 Hz, which has been reported to be associated with enhanced auditory feedback in our previous research. The auditory masking not only significantly increased the low-frequency F0 variability, but also significantly decreased the ratio of the spectral power within 200∼300 Hz to the power within 300∼1000 Hz for the vowel and sentence productions. Gender differences were found in the correlations between the degree of nasal coupling and F0 stability as well as in the LTAS characteristics in response to noise. CONCLUSIONS: Variations in nasal-oral acoustic coupling not only change the formant features of speech signals, but involuntarily influence the auditory feedback control of vocal fold vibrations. Speakers tend to show improved F0 stability in response to a forward-focused voice adjustment.

Increased nasality of connected speech in patients underwent modified Lothrop procedure for refractory chronic rhinosinusitis: Cross-sectional and prospective study.

BACKGROUND: The endoscopic modified Lothrop procedure (EMLP) is performed to create a large frontal neostium in patients who had failed previous frontal sinus surgeries. EMLP causes obvious changes in the volume and anatomy of the sinuses, which may cause a more significant change in nasality. This study aimed to evaluate the changes in nasalance in patients who underwent EMLP by comparing their preoperative nasalance to the established normative values and postoperative nasalance. METHODS: This was a prospective study. Twenty-one patients diagnosed with refractory frontal sinusitis who were indicated to undergo EMLP were enrolled. One hundred one healthy participants were enrolled as norm references. The Nasometer II Model 6400 (KayPENTAX) was used to analyze the nasalance scores. Nasalance scores were tested before surgery and 1 and 3 months after the surgery. RESULTS: The normative references of nasalance were (mean ± SD) 14.6% ± 6.7%, 39.4% ± 8.4%, and 55.8% ± 8.3% for the oral passage, oral-nasal passage, and nasal sentences, respectively. The mean nasalance scores pre-EMLP and 1 and 3 months post-EMLP were 23.2% ± 9.6%, 29.0% ± 9.3%, and 29.9% ± 0.4% for the oral passage; 48.7% ± 10.7%, 54.7% ± 7.7%, and 56.4% ± 7.2% for the oral-nasal passage; and 62.7% ± 10.9%, 69.8% ± 6.7%, and 70.7% ± 6.4% for the nasal sentences, respectively. Compared with the normative references, pre-EMLP nasalance was higher for all the three speech stimuli (t-test, p < 0.05). Post-EMLP nasalance also significantly increased for all the three stimuli at the 1- and 3-month follow-up visits (Paired t-test, p < 0.05). CONCLUSION: EMLP has a short-term impact on resonance; however, long-term follow-up is required for further study.

Obstructive Sleep Apnea and Auditory Dysfunction-Does Snoring Sound Play a Role?

The objective of the study was to investigate the relationship between obstructive sleep apnea (OSA) and auditory dysfunction, and to clarify the role of snoring sounds in contributing to auditory dysfunction. A comprehensive assessment of OSA and the auditory system was performed, including overnight polysomnography, detection of the intra-ear canal snoring sound energy (SSE), pure tone average (PTA), tinnitus pitch matching, the tinnitus handicap inventory (THI), and the Epworth sleepiness scale (ESS). The patients were identified as having tinnitus if their THI score was higher than zero or their tinnitus pitches were matched to specific frequencies. The median age, body mass index, and apnea-hypopnea index score were 41 years, 26.4 kg/m2, and 29.9 events/h, respectively. Among the 50 participants, 46 (92%) had a normal PTA, and only 4 (8%) patients had mild hearing loss. There was no significant difference in PTA among OSA severities (p = 0.52). Among the 50 participants, 33 patients (66%) were identified as having tinnitus. In the tinnitus group (n = 33), the ESS score (p = 0.01) and intra-ear canal SSE of 851-1500 Hz (p = 0.04) were significantly higher than those in the non-tinnitus group (n = 17). OSA patients with a higher ESS score had a higher risk of tinnitus (odds ratio 1.22 [95% CI: 1.01-1.46]). OSA-related auditory dysfunction emerged in tinnitus rather than in hearing impairment. OSA patients with daytime sleepiness had a higher risk of tinnitus. High-frequency SSE can jeopardize cochlea and is a potential mechanism contributing to tinnitus. Detection of snoring sounds through an intra-ear canal device may be more precise in assessing acoustic trauma from snoring sounds to vulnerable auditory system and thus warrants further research.

Response of nasal airway and heart rate variability to controlled nasal breathing.

To investigate the responses of nasal airway and autonomic nervous system (ANS) under controlled nasal breathings. Ten healthy volunteers, aged between 21 and 37 years, were enrolled. The participants breathed either through bilateral nostrils (BNB) or unilaterally through the left nostril (UNB) at 0.25 Hz for 5 min. The electrocardiography was simultaneously recorded and the ANS activities were evaluated using heart rate variability analysis. Nasal airway resistance and related factors were measured by rhinomanometry. The results showed that the mean heartbeat interval during UNB was significantly greater than during BNB. The sympathetic modulation decreased significantly during UNB. The correlations between nasal airway resistance and mean heartbeat interval were significant for both UNB and BNB. The increase of heartbeat intervals during UNB was associated with the decrease of cardiac sympathetic activities. The changes of ANS activities and nasal airway resistance during UNB are similar to the changes caused by a prolonged lying.

Snoring Sound Characteristics are Associated with Common Carotid Artery Profiles in Patients with Obstructive Sleep Apnea.

BACKGROUND: Obstructive sleep apnea (OSA) and snoring have been reported to be modifiable risk factors for thick carotid intima-media thickness (CIMT) and carotid atherosclerosis, which are closely linked to cardiovascular disease. METHODS: This cross-sectional study prospectively recruited 70 participants with OSA and without a history of carotid artery disorder, who primarily sought surgical Intervention. OSA and snoring were assessed with the Epworth Sleepiness Scale, Snore Outcomes Survey, polysomnography, and snoring sound recording. The carotid arteries were evaluated with ultrasonography and divided into three types of carotid artery profiles (normal carotid artery, thick CIMT, or significant carotid atherosclerosis). Multivariate linear/logistic/categorical regressions were performed with the forward selection approaches/logistic least absolute shrinkage and selection operator, as appropriate. RESULTS: Normalized snoring sound energy (301-850 Hz) was independently associated with the carotid intima-media thickness (regression coefficient [ß] = 0.01, standard error [SE] = 0.004, P = 0.03; R 2 = 0.067) and type of carotid profile (ß = 0.40, SE = 0.09, P < 0.001; R 2 = 0.156). Normalized snoring sound energy (4-300 Hz) (ß = -0.10, SE = 0.04, P = 0.01) and female sex (ß = 1.90, SE = 0.94, P = 0.04) were independently related to the presence of carotid stenosis (R 2 = 0.159). The optimal regression model of the type of carotid artery profile included normalized snoring sound energy (301-850 Hz) (ß = 0.33, SE = 0.14, P = 0.03), snoring time (ß = 0.26, SE = 0.13, P = 0.047), female sex (ß = 0.26, SE = 0.13, P = 0.047), and increased age (ß = 0.20, SE = 0.10, P = 0.04) under the control of the Snore Outcomes Survey score, 3% oxygen desaturation index, snoring sound energy (4-1500 Hz), normalized snoring sound energy (851-1500 Hz), cigarette smoking, and hyperlipidemia (R 2 = 0.427). CONCLUSION: Our findings suggested that snoring sound characteristics are associated with carotid artery profiles among early OSA patients who cannot be noticed by ultrasound because organic changes of the carotid artery have not yet started. Future studies are warranted to verify the clinical significance of the results.

Screening Severe Obstructive Sleep Apnea in Children with Snoring.

Efficient screening for severe obstructive sleep apnea (OSA) is important for children with snoring before time-consuming standard polysomnography. This retrospective cross-sectional study aimed to compare clinical variables, home snoring sound analysis, and home sleep pulse oximetry on their predictive performance in screening severe OSA among children who habitually snored. Study 1 included 9 (23%) girls and 30 (77%) boys (median age of 9 years). Using univariate logistic regression models, 3% oxygen desaturation index (ODI3) ≥ 6.0 events/h, adenoidal-nasopharyngeal ratio (ANR) ≥ 0.78, tonsil size = 4, and snoring sound energy of 801-1000 Hz ≥ 22.0 dB significantly predicted severe OSA in descending order of odds ratio. Multivariate analysis showed that ODI3 ≥ 6.0 events/h independently predicted severe pediatric OSA. Among several predictive models, the combination of ODI3, tonsil size, and ANR more optimally screened for severe OSA with a sensitivity of 91% and a specificity of 94%. In Study 2 (27 (27%) girls and 73 (73%) boys; median age, 7 years), this model was externally validated to predict severe OSA with an accuracy of 76%. Our results suggested that home sleep pulse oximetry, combined with ANR, can screen for severe OSA more optimally than ANR and tonsil size among children with snoring.

Changes of rhythm of vocal fundamental frequency in sensorineural hearing loss and in Parkinson's disease.

The neurological control of speech is a complex process that involves phonation organs, respiratory and auditory systems. In the instance of a steady-as-possible sustained phonation, the vocal fundamental frequency (F0) is rhythmic and oscillating in varied degree. The present study examines the changes in the rhythm of F0 in subjects with sensorineural hearing loss (SNHL) as well as in subjects with Parkinson's disease (PD) after being orally administered with dopamine. The sustained steady vocalizations of vowel [a:] from 19 subjects with SNHL and from 13 subjects with normal hearing were collected and statistically compared. In addition, the phonations of 14 subjects with PD before and after oral medication with oral dopamine were collected and statistically compared. The F0 of a phonation was retrieved by digital signal processing of voice signals, and were then analyzed using Fourier transformation to acquire the amplitude of oscillation at different frequency components. Our study showed that subjects with SNHL had significantly larger fluctuation in the low frequency (< 3 Hz) than the subjects with normal hearing. In addition, dopamine medication significantly reduced the fluctuation in the mid-frequency (3-8 Hz) in subjects with PD. Our study indicates that power spectral analysis of F0 may potentially be very useful in the evaluation or detection of SNHL and PD. The rhythms of F0 are produced from neurological controls of phonation and may be used to access clinical diseases by a sustained phonation.

Vestibular evoked myogenic potentials in middle ear effusion.

CONCLUSION: The vestibular evoked myogenic potential (VEMP) responses were significantly affected by middle ear effusion (MEE). The VEMP was either non-responsive or significantly delayed. However, after the conductive hearing loss (CHL) was significantly reduced with tympanic aspiration, the VEMP latencies and asymmetry ratio returned to the range of healthy controls. In addition, the recovery of VEMP response was prompt and immediate. OBJECTIVE: To evaluate the VEMP in various degrees of CHL resulting from MEE and to clarify the responses after the CHL was reduced. MATERIALS AND METHODS: VEMPs were collected from 21 unilateral subjects with MEE (8 male, 13 female, aged 21-79 years) using unilateral tone-burst stimulation. The pure tone audiograms and tympanograms were recorded. The effusion was then cleared with tympanocentesis. The VEMP responses were compared to those of the healthy volunteers and the responses after the MEE was reduced by tympanic aspiration. RESULTS: The pure tone hearing thresholds decreased significantly with tympanic aspiration. Before tympanic aspiration, the VEMP response rate was 67% and increased significantly to 95% (p<0.05) after tympanic aspiration. The latencies of p13 and n23 were significantly prolonged before tympanic aspiration (p<0.01), and shortened to the normal range after tympanic aspiration. The VEMP asymmetry ratio was significantly decreased after tympanic aspiration (p<0.05).