Sensation Level Research Articles

Sensory processing patterns and their relationships to coping and occupational engagement in mental health service users.

Mental health service users often have sensory processing difficulties hampering their ability to cope with mental health problems and occupational engagement. However, there is little knowledge of sensory processing and its relation to these factors. Hence, this current study aims to investigate sensory processing patterns in relation to coping and occupational engagement for the target group. This cross-sectional study involved 97 mental health service users. Sociodemographic information and self-rated questionnaires were administered; Adolescent/Adult Sensory Profile (AASP), Coping Orientation to Problems Experienced Inventory scale (short version) (Brief-COPE), and Profiles of Occupational Engagement among people with Severe mental illness (POES). Statistical analysis included descriptive statistics and multiple linear regression models. This study sits within an RCT project where parts were designed collaboratively with research-educated service users. The result showed strong relationships between sensory processing patterns and occupational engagement. Low levels of occupational engagement were related to high levels of sensory sensitivity, sensation avoiding, and low registration. Whereas, high levels of occupational engagement were related to high levels of sensation-seeking. Concerning coping styles, high levels of emotion-focused coping were related to high levels of low registration, while high levels of avoidant coping styles were related to high levels of sensation-seeking. The findings indicate that occupational engagement and coping styles are related to outcomes of the sensory profile and thus affect how a person with severe mental health problems interprets and reacts to sensory stimuli in daily life.

Auditory decision-making deficits after permanent noise-induced hearing loss

Loud noise exposure is one of the leading causes of permanent hearing loss. Individuals with noise-induced hearing loss (NIHL) suffer from speech comprehension deficits and experience impairments to cognitive functions such as attention and decision-making. Here, we investigate the specific underlying cognitive processes during auditory perceptual decision-making that are impacted by NIHL. Gerbils were trained to perform an auditory decision-making task that involves discriminating between slow and fast presentation rates of amplitude-modulated (AM) noise. Decision-making task performance was assessed across pre- versus post-NIHL sessions within the same gerbils. A single exposure session (2 h) to loud broadband noise (120 dB SPL) produced permanent NIHL with elevated threshold shifts in auditory brainstem responses (ABRs). Following NIHL, decision-making task performance was tested at sensation levels comparable to those prior to noise exposure in all animals. Our findings demonstrate NIHL diminished perceptual acuity, reduced attentional focus, altered choice bias, and slowed down evidence accumulation speed. Finally, video-tracking analysis of motor behavior during task performance demonstrates that NIHL can impact sensory-guided decision-based motor execution. Together, these results suggest that NIHL impairs the sensory, cognitive, and motor factors that support auditory decision-making.

Regression-Based Classification of the Middle-Latency Auditory-Evoked Potentials in Vestibular Migraine and Concussion Patients with Dizziness.

The auditory middle-latency responses (AMLRs) assess central sensory processing beyond the brainstem and serve as a measure of sensory gating. They have clinical relevance in the diagnosis of neurological conditions. In this study, magnitude and habituation of the AMLRs were tested for sensitivity and specificity in classifying dizzy patients with vestibular migraine (VM) and post-concussive syndrome. Twenty-three healthy individuals, 12 concussion and 26 VM patients were recruited. AMLR were recorded performing five blocks of 200 binaural click-stimulations at 60 dB sensation level with a repetition rate of 6.1 Hz. Reduction in P0, Na and Pa magnitudes between blocks was measured. Group classifications were performed through logistic and multiple regression. Among healthy subjects, a consistent P0 and Na habituation can be observed. Concussed subjects show control-like Na habituation, despite a lower magnitude, while P0 habituation was negligible. VM patients showed poor habituation for all waves. Regression analyses suggest that P0 and Na better distinguish healthy subjects from neurological patients, whereas Pa best distinguishes concussion from VM patients. The results support that AMLR habituation can contribute to unraveling different mechanisms of dizziness due to concussion compared to VM, providing insights that can complement routine diagnostic assessments.

Analysis of clinical characteristics and predictive model for effective treatment of tinnitus in patients with transient compound sound therapy

PurposeThis study explored the clinical characteristics of patients with tinnitus who responded to sound therapy and established a predictive model to evaluate the effectiveness of this therapy according to the clinical characteristics.MethodsA retrospective analysis was performed on 991 subjective tinnitus patients who received compound sound therapy in the Department of Otolaryngology of the local hospital from November 2019 to January 2022.ResultsWe found that tinnitus patients with different therapeutic effects had significant differences in the tinnitus side (p = 0.007), tone loudness distortion feedback test (FBT) (p = 0.000), residual inhibition test (RIT) (p = 0.000), tinnitus frequency (p = 0.012) and sensation level (p = 0.023). The corresponding variables were screened by univariate logistic regression, and the selected variables were analyzed using multivariate logistic regression. The results showed that FBT (p = 0.003), RIT (p = 0.000) and tinnitus frequency (p = 0.029) were independent risk factors affecting the efficacy of compound sound therapy. A predictive model and nomogram for the efficacy of compound sound therapy for tinnitus were constructed based on independent risk factors. The area under the curve (AUC) of the model constructed in this study was 0.766 (95% CI = 0.725–0.807), indicating a certain prediction ability. The calibration curve revealed that the predicted results were in good agreement with the actual results.ConclusionThe model can predict the prognosis of tinnitus in patients receiving compound sound therapy and help otolaryngologists make the best clinical decisions regarding tinnitus treatment.

Thermal comfort evaluation using different glazing technologies in an energy model of rural housing in a cold climate

Building energy efficiency, consumption and comfort are aspects to be evaluated in the energy simulation of buildings (BES). However, their results deviate from reality leading to the need to improve their accuracy through calibration. In this regard, a rural house located in a cold climate at more than 3000 meters above sea level, is energetically modeled with its subsequent calibration and evaluation of thermal comfort. The study is developed in four stages, starting with the monitoring of climatological variables and followed by the house energy modeling. Subsequently, manual and iterative calibration is conducted by means of statistical comparison and scatter plots. In this way, a model with more than 80% accuracy between monitored and simulated data is achieved. Based on the previously calibrated model, the thermal comfort is evaluated using different glazing technologies and then, the number of hours for two levels of thermal sensation are evaluated (comfortable and not comfortable). For this purpose, statistical methods such as predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD) are used, which are included in the Design Builder software. This study identified that single bronze glazing technology increased thermal comfort hours by 14.2% with respect to the case study, allowing the development of a methodology that improves thermal comfort through passive heating in rural dwellings in cold climates.

A144: Effect of Reduced Plantar Cutaneous Sensation on Balance Control Among People with Chronic Ankle Instability

PURPOSE: This study aimed to determine whether reduced plantar cutaneous sensation could influence static balance control among people with and without chronic ankle instability (CAI). METHODS: Thirty-one people with CAI (female=7, age=22.03±1.73 years, height=174.41±9.83 cm, body mass=71.79±14.95 kg) and twenty-nine people without CAI (female=5, age=22.86±1.59 years, height=172.81±7.99 cm, body mass=69.04±11.32 kg) were recruited. Static balance controls were represented by the mean displacement of the center of pressure (CoP) in the anteroposterior (AP) and mediolateral (ML) directions on a force plate during unilateral standing with eyes open. The participants placed their bare foot on shaved ice for 10 minutes to reduce plantar cutaneous sensation. Plantar cutaneous sensation at the 5th metatarsal was measured with a set of twenty Semmes-Weinstein monofilaments (SWM) to confirm reduced sensation levels. A higher value of SWM indicated a decreased sensation and higher threshold. Plantar cutaneous sensation threshold and standing tests were conducted before (pre-ice) and after (post-ice) ice immersion. Two-way repeated ANOVA tests were used to analyze data. RESULTS: Plantar cutaneous sensation threshold in the CAI group (pre-ice: 3.11±0.34 gauge, post-ice: 4.15±0.29 gauge, p < 0.001, d=3.29) and non-CAI group (pre-ice: 2.95±0.34 gauge, post-ice: 4.10±0.34, p < 0.001, d=3.38) significantly increased after ice immersion, indicating a significant reduction in the plantar cutaneous sensitivity. A significant interaction was detected in the mean displacement of CoP in the AP direction (p = 0.047, η2 = 0.069). Compared to pre-ice, the mean CoP displacement in the AP direction (pre-immersion: 7.29±0.22, post-immersion: 6.62±0.22, p = 0.002, d = 3.05) decreased in the CAI group while remaining unchanged in the control group after ice immersion. CONCLUSION: The reduction in plantar cutaneous sensation induced by ice immersion enhanced static balance control in individuals with CAI, with no observable effect on those without CAI. The results of this study suggest that people with CAI produced adaptive changes compared to people without CAI, which allows them to maintain balance to avoid injury.

A Prospective Observational Study to Establish a Correlation Between Tinnitus and Hearing Loss

Introduction: The prevalence of tinnitus in adults with hearing problems is very high (59 - 86%). Both tinnitus and sensorineural hearing loss can occur when there is damage throughout the auditory pathway from the inner ear to auditory cortex. Our aim of the study was to evaluate the prevalence of hearing loss in patients with tinnitus and to assess the association between tinnitus and hearing loss. Materials and methods: This prospective observational study was conducted for 12 months between May 2022 and April 2023. 60 patients of both the sexes >15 years of age presenting with tinnitus in one or both ears were included in our study. Mentally ill and/or intoxicated patients were excluded. After clinical examination patients underwent Pure Tone Audiometry - average was calculated across 500, 1000, 2000, 4000 Hz in terms of air conduction, bone conduction and air bone gap. Hearing loss was classified as conductive, sensorineural and mixed types. Tinnitus pitch and loudness matching was done for which opposite ear was taken as test ear. In cases of bilateral tinnitus with equal intensity, right ear was taken first as test ear. In case of bilateral tinnitus with unequal intensity, ear with higher intensity tinnitus was tested first. Sensation level of tinnitus was calculated by subtracting the hearing loss threshold from tinnitus loudness in decibel. Result: In our study the mean age was found to be 44.20± 17.01years, with a male preponderance, and maximum number of cases complaining of left sided tinnitus. In an attempt to find a correlation between tinnitus and hearing loss, in right and left ears separately, ‘P’ value calculated to be <0.001.We also attempted to find a correlation between highest hearing loss and tinnitus loudness. We found that relative coefficient, ‘r’ being 0.309 on right side and 0.270 on left side. ‘P’ value on right is 0.097 and on left is 0.117. Conclusion: Since most of the cases of tinnitus also complaints of hearing loss, so it is necessary to identify a relation between the two. If a relation between tinnitus and hearing can be identified, it helps to identify the pathophysiology, which will further be helpful to plan the line of management. There are very limited number of studies conducted. Our study suggests a definite relation between tinnitus and hearing loss though there is no statistically significant correlation found between tinnitus loudness and highest hearing loss in the same ear.

Investigation of Presentation Levels for Optimal Use of NU-6 Ordered by Difficulty Version II Word Lists.

The current work sought to identify the optimal presentation levels for the NU-6 ordered-by-difficulty (OBD) abbreviated word lists. An optimal presentation level would yield a listener's highest word recognition score (WRS; known as phonetically balanced [PB] max) and allow the use of a shortened test protocol. A protocol based on the dB sensation level (dB SL) at 2000 Hz was used as a starting point. It is not known if these two commonly used time-saving approaches can be used in combination to obtain optimal results. WRSs were obtained at multiple levels. The initial level was based on the hearing threshold at 2000 Hz and was either increased or decreased. For listeners with hearing loss, uncomfortable listening (UCL) levels were measured, and a word list was presented 5 dB below the UCL. Thirty-four adults with (25) and without (9) hearing loss, who were recruited via flyers and direct contact, participated in this study. A descriptive analysis was conducted to identify the level needed to obtain PB max using OBD word lists with the least number of words. In most cases, the initial presentation level did not yield PB max and required more than 10 words. It is recommended that the presentation level for NU-6 OBD word lists be at least 30-40 dB SL relative to the hearing threshold at 2000 Hz with a minimum presentation level of 35 dB HL. If this is not feasible, the presentation of these words at UCL-5 is recommended.

Pacing sensation with a second generation intercostal extravascular ICD lead

Abstract Background/Introduction An investigational intercostal extravascular ICD lead (EV-ICD Lead) has been developed to provide antitachycardia pacing and shock treatment of ventricular tachyarrhythmias when connected to a commercially available ICD pulse generator. Unlike other available extravascular ICD systems that achieve pacing with ring electrodes which transmit undirected current to cardiac and non-cardiac tissue alike, the intercostal EV-ICD Lead uses button-shaped electrodes backed by an insulative paddle to direct current toward excitable myocytes while minimizing undesired excitation of the adjacent tissues. Purpose The purpose of this analysis was to evaluate pacing sensation with the intercostal EV-ICD Lead connected to a commercially-available ICD pulse generator programmed to the maximum voltage output and pulse width settings. Methods In the STEP ICD Study (n=20), pacing sensation was evaluated at the pre-discharge visit while pacing at the maximum programmable voltage output (7.5 or 8.0 V, depending on manufacturer) and pulse width (1.5 or 2.0 ms). Sensation was reported by the patient as one of four choices: No Sensation, Sensation Only, Tolerable Pain or Intolerable Pain. Results Pacing sensation was assessed in 18 of 20 patients. One (1) patient did not undergo a pacing evaluation due to atrial fibrillation with rapid ventricular response. Responses were as follows: No Sensation in 4 (22%) patients, Sensation Only in 10 (56%) patients, Tolerable Pain in 3 (17%) and Intolerable Pain in 1 (6%). In no patient was the pain so severe that pacing capture threshold testing could not be completed. Of note, the single report of intolerable pain was only reported in the sitting posture. When tested supine, the patient reported sensation only. Conclusion(s) The design of the investigational intercostal EV-ICD Lead, with button-shaped electrodes backed by an insulative paddle, produced low levels of patient sensation at maximum output and pulse width. These sensation levels represent an improvement over designs that employ ring electrodes and indicate that antitachycardia pacing will be well tolerated with the novel EV-ICD Lead. These results corroborate the predictions about patient discomfort from in silico models.

Industry-Scalable Reusable Textile Electrodes for Neurostimulation Applications.

Neurostimulation delivers electrical pulses to modulate neuromuscular activity. Commonly used in medical interventions from pain relief to rehabilitation, neurostimulation typically uses manually placed hydrogel electrodes over the treated region. However, this method limits interventions requiring frequent, long-term daily use. To address this, novel fully textile electrodes are developed using industrial programmable knitting machines. These electrodes are designed to be washable, reusable, flexible, and breathable, with embedded interconnects. Textile electrodes are made of yarns with stainless steel and PEDOT-coated stainless steel conductive components. The electrodes' performance are compared with gel electrodes, characterizing impedance, sensorimotor stimulation thresholds, recruitment of induced movements, sensation levels, and perceived sensations. The effects of residential wash cycles and continuous use duration are also investigated. The proposed electrodes are found to perform similarly to hydrogel electrodes in all characterized metrics. No degradation in electrode performance is found after at least 30 wash cycles. Electrodes remained functionally intact after 1000 cycles of stretch loading at 50% of break strain. The textile electrodes consistently induced comfortable sensorimotor responses for at least six hours after donning. The proposed textile electrodes offer a novel and effective solution for neurostimulation interventions, paving the way for integration into smart garments and long-term wearable health technologies.

Disentangling Contact Location for Stretchable Tactile Sensors from Soft Waveguide Ultrasonic Scatter Signals

Flexible tactile sensors have the ability to provide unparalleled levels of tactile sensation, including information regarding roughness, contact force, and contact location. However, it remains a challenge to achieve precise contact location sensing that is decoupled from sensor strain and touching forces. This paper proposes a novel data‐driven approach for force contact location sensing (FCLS) with the influence of sensor strain and forces based on scatter signals (SS) of the ultrasonic waveguide. First, the envelope of the force contact scatter signal (FCSS) is extracted via the Hilbert transform, which retrieves the global features of SS. The time‐frequency spectrogram is obtained via continuous wavelet transform, which extracts the local features of SS. Second, a deep convolutional neural network (CNN) is utilized to extract these features separately and concentrate them together. Third, based on the outputs of the CNN, a multilayer perception regression model is applied to acquire the force contact location. The experimental results indicate that the accuracy of the proposed FCLS method has a mean absolute error of 0.627 mm and a mean relative error of 3.19%. This research provides a foundation for further multimodal sensing using ultrasonic waveguides and its application in robotic sensing.

Auditory decision-making deficits after permanent noise-induced hearing loss.

Loud noise exposure is one of the leading causes of permanent hearing loss. Individuals with noise-induced hearing loss (NIHL) suffer from speech comprehension deficits and experience impairments to cognitive functions such as attention and decision-making. Here, we tested whether a specific sensory deficit, NIHL, can directly impair auditory cognitive function. Gerbils were trained to perform an auditory decision-making task that involves discriminating between slow and fast presentation rates of amplitude-modulated (AM) noise. Decision-making task performance was assessed across pre-versus post-NIHL sessions within the same gerbils. A single exposure session (2 hours) to loud broadband noise (120 dB SPL) produced permanent NIHL with elevated threshold shifts in auditory brainstem responses (ABRs). Following NIHL, decision-making task performance was tested at sensation levels comparable to those prior to noise exposure in all animals. Our findings demonstrate NIHL diminished perceptual acuity, reduced attentional focus, altered choice bias, and slowed down evidence accumulation speed. Finally, video-tracking analysis of motor behavior during task performance demonstrates that NIHL can impact sensory-guided decision-based motor execution. Together, these results suggest that NIHL impairs the sensory, cognitive, and motor factors that support auditory decision-making.

Proprioceptive Sensation Levels of The Elbows of Physically Disabled Athletes.

The aim of this study was to compare elbow joint proprioception measurements between physically disabled individuals who are active in sports and those who are not. The study included 30 athletes, 30 sedentary individuals, 30 physically disabled athletes, and 30 physically disabled sedentary individuals as volunteers. Elbow joint proprioception measurements were conducted using a sensitive digital goniometer with a precision of 1 degree. The joint position sense test method was used to perform the active angle repetition technique. Target angles were determined to be 30°, 60°, and 120°. A significant difference was observed in the comparison of proprioception between the dominant and non-dominant elbow joints of athletes and physically disabled sedentary individuals (p<0.05). Elbow joint proprioception was found to be highest in physically disabled athletes at the target angles. Conversely, the lowest elbow joint proprioception levels were found in physically disabled sedentary patients compared with the other groups.

Effect of stimulus duration on estimates of human cochlear tuning

Auditory masking methods originally employed to assess behavioral frequency selectivity have evolved over the years to infer cochlear tuning. Behavioral forward masking thresholds for spectrally notched noise maskers and a fixed, low-level probe tone provide accurate estimates of cochlear tuning. Here, we use this method to investigate the effect of stimulus duration on human cochlear tuning at 500 Hz and 4 kHz. Probes were 20-ms sinusoids at 10 dB sensation level. Maskers were noises with a spectral notch symmetrically and asymmetrically placed around the probe frequency. For seven participants with normal hearing, masker levels at masking threshold were measured in forward masking for various notch widths and for masker durations of 30 and 400 ms. Measurements were fitted assuming rounded exponential filter shapes and the power spectrum model of masking, and equivalent rectangular bandwidths (ERBs) were inferred from the fits. At 4 kHz, masker thresholds were higher for the shorter maskers but ERBs were not significantly different for the two masker durations (ERB30ms=294 Hz vs. ERB400ms=277 Hz). At 500 Hz, by contrast, notched-noise curves were shallower for the 30-ms than the 400-ms masker, and ERBs were significantly broader for the shorter masker (ERB30ms=126 Hz vs. ERB400ms=55 Hz). We discuss possible factors that may underlay the duration effect at low frequencies and argue that it may not be possible to fully control for those factors. We conclude that tuning estimates are not affected by maker duration at high frequencies but should be measured and interpreted with caution at low frequencies.

Attenuation and distortion components of age-related hearing loss: Contributions to recognizing temporal-envelope filtered speech in modulated noise.

Older adults with hearing loss may experience difficulty recognizing speech in noise due to factors related to attenuation (e.g., reduced audibility and sensation levels, SLs) and distortion (e.g., reduced temporal fine structure, TFS, processing). Furthermore, speech recognition may improve when the amplitude modulation spectrum of the speech and masker are non-overlapping. The current study investigated this by filtering the amplitude modulation spectrum into different modulation rates for speech and speech-modulated noise. The modulation depth of the noise was manipulated to vary the SL of speech glimpses. Younger adults with normal hearing and older adults with normal or impaired hearing listened to natural speech or speech vocoded to degrade TFS cues. Control groups of younger adults were tested on all conditions with spectrally shaped speech and threshold matching noise, which reduced audibility to match that of the older hearing-impaired group. All groups benefitted from increased masker modulation depth and preservation of syllabic-rate speech modulations. Older adults with hearing loss had reduced speech recognition across all conditions. This was explained by factors related to attenuation, due to reduced SLs, and distortion, due to reduced TFS processing, which resulted in poorer auditory processing of speech cues during the dips of the masker.

Pharmacokinetics, safety, and efficacy of Fuqi Guben Gao in the treatment of kidney-yang deficiency syndrome: a randomized, double-blind phase I trial.

Introduction: Fuqi Guben Gao (FQGBG) is a botanical drug formulation composed of FuZi (FZ; Aconitum carmichaelii Debeaux [Ranunculaceae; Aconiti radix cocta]), Wolfberry (Lycium barbarum L. [Solanaceae; Lycii fructus]), and Cinnamon (Neolitsea cassia (L.) Kosterm. [Lauraceae; Cinnamomi cortex]). It has been used to clinically treat nocturia caused by kidney-yang deficiency syndrome (KYDS) for over 30years and warms kidney yang. However, the pharmacological mechanism and the safety of FQGBG in humans require further exploration and evaluation. Methods: We investigated the efficacy of FQGBG in reducing urination and improving immune organ damage in two kinds of KYDS model rats (hydrocortisone-induced model and natural aging model), and evaluated the safety of different oral FQGBG doses through pharmacokinetic (PK) parameters, metabonomics, and occurrence of adverse reactions in healthy Chinese participants in a randomized, double-blind, placebo-controlled, single ascending dose clinical trial. Forty-two participants were allocated to six cohorts with FQGBG doses of 12.5, 25, 50, 75, 100, and 125g. The PKs of FQGBG in plasma were determined using a fully validated LC-MS/MS method. Results: FQGBG significantly and rapidly improved the symptoms of increased urination in both two KYDS model rats and significantly resisted the adrenal atrophy in hydrocortisone-induced KYDS model rats. No apparent increase in adverse events was observed with dose escalation. Major adverse drug reactions included toothache, thirst, heat sensation, gum pain, diarrhea, abdominal distension, T-wave changes, and elevated creatinine levels. The PK results showed a higher exposure level of benzoylhypaconine (BHA) than benzoylmesaconine (BMA) and a shorter half-life of BMA than BHA. Toxic diester alkaloids, aconitine, mesaconitine, and hypaconitine were below the lower quantitative limit. Drug-induced metabolite markers primarily included lysophosphatidylcholines, fatty acids, phenylalanine, and arginine metabolites; no safety-related metabolite changes were observed. Conclusion: Under the investigated dosing regimen, FQGBG was safe. The efficacy mechanism of FQGBG in treating nocturia caused by KYDS may be related to the improvement of the hypothalamus-pituitary-adrenal axis function and increased energy metabolism. Clinical Trial Registration: https://www.chictr.org.cn/showproj.html?proj=26934, identifier ChiCTR1800015840.

Evaluation of Virtual Reality in the Reduction of Pain During Dressing Changes in Patients With Burn Wounds: A Pilot Study.

Burn injuries are among the most common life-threatening injuries for which medical attention is sought, and are accompanied by intense, severe pain, particularly during treatment. Burn therapy pain management with opioid and nonopioid analgesics is often insufficient when administered alone. Virtual reality (VR) interfaces provide an immersive experience that has demonstrable therapeutic benefits, including distraction from, and reduction of, pain. In this interventional pilot study, we assessed the correlation between VR and passive distraction and pain tolerance during burn wound treatment. This pilot study assessed patients undergoing burn wound dressing changes while receiving both pharmacological and VR intervention. Questionnaires and evaluation forms were subjectively completed by both patients and medical staff before and after treatment, and clinical metrics were recorded throughout the treatment. Forty-one patients ≥18 years old and 76.9% male that had primarily undergone ≥4 dressing changes before the study were included. Correlations were found between VR engagement during treatment and a decrease in subjective levels of nausea, anxiety, and pain sensation. Furthermore, high levels of VR engagement were correlated with high levels of VR enjoyment. These results suggest that highly engaging and enjoyable VR interfaces may reduce sensations of anxiety and pain in burn patients during dressing changes. Furthermore, these data suggest that VR technology may be applied as an adjunct therapy to pharmacological treatment in the standardization of burn wound care management. Further studies with control groups and larger sample populations are needed for better quantification of these benefits.

Acoustic change complex (ACC) as a new tool in assessment of hearing aid performance in children

ObjectiveTo evaluate the clinical use of acoustic change complex (ACC) as an objective tool in children who use hearing aids (H.As) and explore how far ACC threshold could be correlated to behavioral measures.Study designSixty Arabic-speaking children (34 boys & 26 girls) using binaural H.As participated in the present study. Their age ranged from 6 to 12 years. The short stimulus used in the present study to elicit ACC response was “gap in tone.” Evaluation of H.As of children was performed in the form of questionnaire, aided sound field thresholds, central auditory tests, and aided/unaided cortical ACC recordings. The replicated ACC waveforms were collected and analyzed, and the aided ACC responses were compared with unaided ACC in addition to correlation of ACC-GDT to behavioral thresholds/scores.ResultsThe highest percent of ACC detectability achieved with gap in tone with 50-ms duration. Percent detectability reached 65% in aided condition and decreased to 25% in unaided test condition. The aided ACC wave morphology showed no significant difference when compared with unaided condition; however, a significant decrease in ACC latency was observed in the aided condition. The ACC response was elicited easily at 40-dB sensation levels or at MCL in both conditions. The ACC-GDT showed correlation to questionnaire scores rather than behavioral test (AFT).ConclusionsACC to relatively short duration stimulus can be successfully recorded in hearing-impaired children in aided and unaided conditions. ACC response parameters (detectability and P1 latency) can reflect the benefit from H.As as an objective measure in evaluation of young children and difficult to test subjects with the usual subjective measures, and finally, ACC-GDT may add a predictive value to questionnaire scores which may help in case of inability of parents or caregivers to fulfill the entire questionnaire items.

Integrating the Living Wall with Mechanical Ventilation to Improve Indoor Thermal Environment in the Transition Season

A living wall, when integrated with a mechanical ventilation system, can effectively improve the indoor thermal environment and reduce indoor CO2 concentration during the transition season. In this study, a control experiment was conducted to analyze the effect of a living wall integrated with mechanical ventilation (LW-V) on indoor air quality. During the experiment, indoor air temperature, relative humidity, indoor air speed, and CO2 concentration were measured, while the skin temperature was monitored and subjective questionnaires were administered to 60 subjects. The results show that the indoor environment was effectively improved by employing the LW-V system, with the average indoor temperature decreasing by 1.45 °C, while relative humidity increased by 19.1%. Due to the plant photosynthesis, CO2 concentrations were reduced by 13.83 ppm. Meanwhile, the mean skin temperature was reduced by 0.18 °C and was closer to the neutral mean skin temperature. Questionnaire analysis reveals the LW-V system improved overall air freshness sensation and thermal comfort level by 1.09 and 0.53, respectively. The LW-V system improved the indoor thermal environment as well as air quality during the transition season significantly.

The Rapid Decline in Interaural-Time-Difference Sensitivity for Pure Tones Can Be Explained by Peripheral Filtering.

The interaural time difference (ITD) is a primary horizontal-plane sound localization cue computed in the auditory brainstem. ITDs are accessible in the temporal fine structure of pure tones with a frequency of no higher than about 1400Hz. How listeners' ITD sensitivity transitions from very best sensitivity near 700Hz to impossible to detect within 1 octave currently lacks a fully compelling physiological explanation. Here, it was hypothesized that the rapid decline in ITD sensitivity is dictated not by a central neural limitation but by initial peripheral sound encoding, specifically, the low-frequency (apical) portion of the cochlear excitation pattern produced by a pure tone. ITD sensitivity was measured in 16 normal-hearing listeners as a joint function of frequency (900-1500Hz) and level (10-50dB sensation level). Performance decreased with increasing frequency and decreasing sound level. The slope of performance decline was 90dB/octave, consistent with the low-frequency slope of the cochlear excitation pattern. Fine-structure ITD sensitivity near 1400Hz may be conveyed primarily by "off-frequency" activation of neurons tuned to lower frequencies near 700Hz. Physiologically, this could be realized by having neurons sensitive to fine-structure ITD up to only about 700Hz. A more extreme model would have only a single narrow channel near 700Hz that conveys fine-structure ITDs. Such a model is a major simplification and departure from the classic formulation of the binaural display, which consists of a matrix of neurons tuned to a wide range of relevant frequencies and ITDs.