Relative Discomfort Research Articles

Factors Associated With Comfort Using Telemedicine for Upper Limb Specialty Care

There is a growing interest in diagnosis and treatment through telemedicine because of its convenience, accessibility, and lower costs. There are clinician and patient barriers to wider adoption of telemedicine. To support the effective and equitable use of telemedicine, we investigated the patient, illness, and surgeon factors associated with the specialist level of comfort in providing upper limb care via telemedicine. Seventy-five upper-extremity musculoskeletal specialists completed an online survey-based experiment in which they viewed 12 patient scenarios with randomized patient age, gender, diagnosis, pain intensity, and patient preference for surgical treatment (yes or no) and rated their comfort with telemedicine from 0, no comfort, to 10, complete comfort. The participants were able to provide a rationale for their stance in open text boxes. We recorded the following specialist factors: gender, location of practice, years in practice, subspecialty, the supervision of trainees, and surgeon-rated importance of a physical examination. In a multivariable analysis, greater surgeon comfort using telemedicine was associated with nontrauma conditions, four specific diagnoses, and patients who did not have severe pain. Lower surgeon comfort with telemedicine was associated with the higher clinician-rated importance of a hands-on physical examination and supervising trainees. Text-based reasons provided for relative comfort with telemedicine included nonsurgical treatment and facility of diagnosis based on interviews alone. Text-based reasons for relative discomfort with telemedicine included a perceived need for a hands-on physical examination and a preference for an in-person conversation for specific discussions, including scheduling surgery. Greater specialist enthusiasm for telemedicine is associated with personal preferences regarding the upper-extremity condition, patients with less severe pain, and a willingness to forego a hands-on examination. Utilization of telemedicine for upper-extremity specialty care may be facilitated by diagnosis-specific care strategies and strategies for video examination, with a focus on tactics that are effective for people with more intense symptoms.

Electric bike level of service: A review and research agenda

With the emerging demand for electric bikes (e-bikes), the design of sustainable mobility infrastructure should account for the level-of-service (LOS) of e-bikes. However, knowledge about e-bike LOS (ELOS) is scarce. We review recent advancements in hindrance-based approaches and microsimulation models to provide insights into the development of ELOS measures for off-road facilities. We discuss challenges associated with the data collection and existing LOS estimation approaches, all of which help shape future research agendas to develop the ELOS index. Our review suggests that future hindrance-based studies should focus on quantifying relative discomfort generated due to passing and meeting encounters. Similarly, future microsimulation-based LOS studies should improve the physical model to mimic meeting event frequencies and develop models for the homogeneous flow of e-bikes. These findings are crucial to integrating hindrance-based and microsimulation approaches in developing the ELOS index, an essential metric for the ex-ante and ex-post evaluation of off-road facilities.

PSIV-5 Definition of environmental variables and critical periods to evaluate heat tolerance in maternal-line pigs based on single-step genomic reaction norms

Abstract Heat stress (HS) is a major welfare and economic issue in the swine industry. However, it is not a trivial task to appropriately quantify the environmental HS. Therefore, this study aimed to 1) define the critical periods and environmental descriptors (based on public weather station information) to evaluate heat tolerance (HT); and 2) estimate genetic parameters for HT in Large White pigs. The traits included in this study were: weaning weight (WW; kg), off-test weight (OTW; kg), total number of piglets born (TNB), number of piglets born alive (NBA), and number of piglets weaned (WN). The number of phenotypic records ranged from 6,059 (WN) to 172,984 (TNB), and genotypes were available for 8,686 animals. Seven climatic variables (maximum, minimum and average temperatures, average relative humidity, dew point, discomfort index and temperature-humidity index) based on public weather station records were compared based on three criteria [GxE estimate as measured by the slope term; theoretical accuracy of the genomic estimated breeding values (GEBV); deviation of GEBV per environmental value]. Relative humidity (for WN and WW) and maximum temperature (for OTW, TNB, and NBA) are the recommended environmental gradients for the studied traits. The acute HS (average of 30 days before measurement date) was the critical period recommended for OTW. For WN and WW, a period of 34 days prior to farrowing up to weaning is recommended. For TNB and NBA, the critical period of 20 days prior breeding to 30 days into gestation is recommended. In general, WN and WW were largely affected by the environment, while the remaining traits showed moderate correlations (OTW, TNB, and NBA). Heritabilities estimated for HT ranged from 0.08 (WW) to 0.25 (OTW). In summary, these results suggest that there is genotype-by-environment interaction for all traits analyzed, and genetic progress can be achieved through genetic selection.

Heterogeneous consumers in the Euro-Area, facing homogeneous monetary policy: Tale of two large economies

This study examines consumer behavior in the Euro-Area in response to monetary policy changes. Selecting two major Euro-Area economies, we apply factor model to investigate how German and French consumers update their macroeconomic expectations. Results at both aggregate and disaggregated levels show asymmetries in consumer responses to different monetary policy stances. We find sizable differences in the way German consumers adjust their expectations compared to the French consumers. While we record inconsistencies across different consumer expectations, we also find behavioral differences in the consumer from similar groups across both countries. The paper concludes that though consumers update their expectations immediately to a monetary policy change, French consumers show a relative discomfort and lesser confidence in the post-recession period despite accommodative moves by the European Central Bank (ECB).

Virtual support for remote proctoring in TAVR during COVID-19.

ObjectivesThe current report describes a single operator's experience of the first use of smartglass technology as a facilitator of virtual support during TAVR proctoring.BackgroundRestricted gatherings and containment measures during the ongoing COVID‐19 pandemic have a major impact on daily clinical practice. Interaction between peers is crucial in science, clinical practice, and education. In addition, there is also a growing importance of proctoring in interventional cardiology for structural heart disease. Virtual support may facilitate the wide implementation of remote proctoring.MethodsA collaboration between a smartglass provider (Rods & Cones) and self‐expandable transcatheter aortic heart valve system (Medtronic) was initiated and tested extensively prior to TAVR procedures. Two cases were randomly selected for remote support. The light‐weight smartglass consisted of a full HD central camera, a 720p ×5 optical zoom camera, built‐in LED light, speaker and earphone jack, and an external visor to project data in a nonobstructive manner in the operators' view.ResultsPreprocedural detailed discussion of the cases between the proctor and the operator occurred via teleconferencing. Successful procedural virtual support was determined by the presence of a session coordinator, high quality of the central camera, high‐speed and stable wireless internet connection. Limitations were the relative discomfort of the earpieces, discordance between the central and zoom camera and the absence of visual fixation during head motions.ConclusionIn a highly complex and demanding context such as TAVR, remote proctoring by means of virtual support is feasible and efficacious.

Increasing the energy flexibility of existing district heating networks through flow rate variations

The possibility of recovering waste and renewable heat in urban areas has made district heating networks one of the key infrastructures for decarbonising the heating sector in Europe. The ability to shift the heat production over time is an important asset to improve the competitiveness of both new and existing networks. To this purpose, the present study evaluates the flexibility potential provided by the water volume enclosed in the network pipelines using the district heating network of Verona (Italy) as a case study.Given the users heat demand in two representative weeks, computer simulations were carried out to calculate the network's thermal response to circulating flow rate variations. The latter were designed to cause an early or late shift in the daily peak thermal load. The local temperature drop at the users substations compared to the current situation was used as a relative discomfort indicator. The simulations were carried out using the model NeMo, which has been attached as supplementary material to this publication. The simulation results show that the network pre-charge strategy achieves significant benefits in terms of both peak shaving and load shifting with a limited impact on discomfort for the users. Furthermore, the paper shows that the available storage capacity of the network is significantly influenced by the duration of the flow adjustment, by the average velocity of the heat carrier fluid and by the daily heat demand pattern. Finally, it is shown that the energy flexibility of the network also depends on its topology. In this regard, the article provides preliminary indications on the number and position of the bypass pipes needed to implement the proposed flow rate variations.In conclusion, the article shows that the thermal inertia of the heat carrier fluid is an interesting source of flexibility for existing networks, and the results highlight its potential and limitations.

Performance on Video-Based Situational Judgment Test Items: Simulated Interracial Interactions

Individuals are known to categorize others into social groups based on cues like race and gender and to experience relative discomfort when interacting with “outgroup” members. Two experimental studies were used to examine whether actor demographic cues in situational judgment assessment items completed by test takers in a simulated employee selection context may lead to differences in their performance and reactions to the hiring organization. In both studies, test takers assumed the perspective of actors shown in video-based scenarios and indicated how they would respond to interaction partners (IPs) to whom they were racially similar or dissimilar. In Study 1, a given test taker responded to IPs of a constant gender; in Study 2, IPs’ gender varied across scenarios within each condition. In Study 1, Black test takers spent more time and scored better on two of the four scenarios when responding to racially similar IPs. These effects were not found in Study 2, but demographic cues showed new interactive effects on performance and reactions. We discuss the implications of different findings across the two studies.

The impact of innovation-related perception on consumer acceptance of food innovations – Development of an integrated framework of the consumer acceptance process

Innovations are an important part of the further advancement of societies in general as well as of companies in particular. Individuals can benefit from the advantages of innovations, while companies can maintain or increase their market share and profitability. However, especially in the food sector, scientific or technological innovations often encounter mistrust and rejecting reactions from consumers, resulting in decreasing acceptance of those innovations. Therefore, this paper aims to gain a deeper comprehension of consumer acceptance of innovative food products as well as to identify antecedent factors of innovation-related perception. For the empirical investigation of our conceptualized model, an online survey was conducted in Germany (n = 617) and the collected data were analyzed through structural equation modeling. The results confirmed a high predictive power of the multi-dimensional model of consumer acceptance. Our first major finding indicates that relative advantage, naturalness, novelty, and discomfort are the most important driving factors of the innovation-related perception of food products. Further important findings show that innovation-related perception has a strong positive and highly significant impact on customer perceived value, respectively a strong negative and highly significant impact on the customer perceived risk. In summary, innovation-related perception, customer perceived value, as well as customer perceived risk, are all important variables related to the acceptance of an innovative food product. The food sector can benefit from the insights provided by this study to communicate and market their products accordingly to the results to reduce mistrust and increase acceptance of food innovations on the consumer side.

Evaluation of Human Discomfort from Combined Noise and Whole-Body Vibration in Passenger Vehicle

Exposure to noise and whole-body vibration (WBV) has been a key element in determining comfort levels in transportation systems. In the automotive industry, researchers and engineers continuously work on reducing noise and vibration levels to minimize discomfort. Noise annoyance in vehicles results from structure-borne as well as air-borne noise from vehicle powertrain, tires and aeroacoustics. Whole-body vibration affects vehicle passenger comfort at the seat pan, back rest and feet. The objective of this research is to evaluate the comfort level of seated passengers in a vehicle from noise and whole-body vibration by considering both separate and combined modality. The noise and vibration data were recorded and analysed in two vehicles on the same highway road with four different speeds. The vibration exposure in vehicle were evaluated based on ISO2631-1:1997. Noise exposure was based on A-weighted sound pressure level. The combined discomfort on noise and vibration were quantified. The vibration results identified clear dominant of z-axis vertical vibration on seat pan, backrest and feet in both vehicles. The discomfort of combined noise and vibration showed that vehicle B caused a higher discomfort level at the high vehicle speed of 90 km/h and 110 km/h. The Relative Discomfort Indicator (RDI) were introduced to compare levels of discomfort from noise and vibration in different vehicles with varying speeds. The result suggests that the RDI value for vehicle A relative to vehicle B is negative at higher vehicle speed which further indicates that at higher speed, vehicle B have a higher discomfort level compared to vehicle A. The RDI value is expected to be useful for automotive Noise, vibration and harshness (NVH) improvement.

Response to White Light Emitting Diode Aviation Signal Lights Varying in Correlated Color Temperature

Airfield lighting for runways and taxiways is currently undergoing a transition from filament-based incandescent sources to light emitting diodes (LEDs). Although models to assess the relative brightness, discomfort glare, and peripheral detectability of signal lights such as those used for aviation exist, their applicability to white LED airfield lighting has not been verified independently. A series of three experiments was conducted to compare white LED sources, having correlated color temperatures of 2,700 K and 5,900 K, in terms of their relative brightness, discomfort glare, and peripheral detectability. The perceived brightness and discomfort glare from the light sources closely matched predictions from the published models, demonstrating the usefulness of these models at characterizing these responses in airfield lighting. In the case of peripheral detectability, there was little to no difference in how quickly the two LEDs were perceived at low light levels, suggesting that there is no need to consider spectral differences between light source spectra for this response when the intensities are similar to those used in the present study.

IL-33 mast cell axis is central in LL-37 induced bladder inflammation and pain in a murine interstitial cystitis model

Interstitial cystitis (IC), also known as painful bladder syndrome (PBS), is a debilitating chronic condition that afflicts over 3 million women above the age of 18 in the U.S., and most patients fail to respond to current treatment options. Mast cells have previously been implicated as both a diagnostic and prognostic marker in IC/PBS. Patients with IC/PBS have been shown to have elevated levels of IL-33, a cytokine released in response to tissue insult, in their urine. We hypothesize that mast cell-mediated inflammation induced from IL-33 may play an important role in initiating pain and inflammation in IC/PBS. A human cathelicidin, LL-37, which is found at elevated levels in IC/PBS patients, was used to induce an IC/PBS-like state of inflammation and bladder pain in mast cell deficient C-kit (−/−) and wild type C57Bl/6 (WT) mice. Inflammation was quantified using myeloperoxidase (MPO) expression in bladder tissues measured via ELISA. Response rate to suprapubic stimulation from von Frey filaments was used to assess the relative pain and discomfort. Both types of mice increased IL-33 expression in response to LL-37 exposure. However, mast cell deficient mice demonstrated significantly lower levels of inflammation (p < 0.001) and reduced pain response (p < 0.001) compared to WT mice. These findings implicate an IL-33-mast cell dependent axis with a potential etiology of pain and inflammation in IC/PBS. Future therapeutics aimed at targeting the IL-33 - mast cell axis could potentially serve as useful targets for treating IC/PBS.

NIRS-based experimental evaluation of driver back fatigue during long-term driving

ABSTRACTMost research on the relationship between driver fatigue, driving comfort, stability and other factors related to driving has consisted subjective assessments via surveys. Bio-signal measurements allow more objective evaluations but the measurement processes and types are very complicated, and measurement signals are sensitive to noise. To address this issue, this paper attempts to quantify driver fatigue by measuring and analyzing hemodynamic responses with near-infrared spectroscopy. The oxygen concentration changes in the erector spinae muscle were measured for the same subjects when driving a vehicle on a highway for a long time, in one of two driving postures: posture A based on the seat status of the average male body type in South Korea (a 107.7° torso angle, 109.1° chair back angle and 561.0 mm seat x-axis position posture) and Posture B with the chair back angle adjusted by −10° from posture A and the seat moved 4 cm back. A survey was carried out on the degree of lumbar discomfort. The analysis of the degree of relative fatigue, based on driver posture utilizing a mathematical model for the physiological system of lower-back fatigue, showed that posture B is relatively uncomfortable compared to posture A by approximately 41%. The results of analyzing the degree of relative discomfort with regard to driver posture using a mathematical model allow the verification that interpreting the relative degree of discomfort based on the changes in the oxygen concentration at a particular time is possible, and the experimental results show the usefulness of the proposed method.

Visual discomfort and flicker

Flickering lights can be uncomfortable to look at and can induce seizures in observers with photosensitive epilepsy. However, the temporal characteristics contributing to these effects are not fully known. In the spatial domain, one identified source of visual discomfort is when images have Fourier amplitude spectra that deviate from the natural (∼1/frequency, 1/f) statistical characteristics of natural scenes, especially if they contain excess energy at the medium frequencies at which the visual system is most sensitive. We tested for analogous effects in the temporal domain, manipulating both the amplitude and phase spectra of the flicker. Participants judged the relative discomfort of temporal luminance variations in a pair of uniform 17° fields with different temporal modulations. In general, discomfort increased with deviations from natural amplitude spectra, particularly those with excess energy at medium frequencies or biased toward sharper spectra. These ratings of discomfort were also consistent with ratings of how natural the modulations appeared. However, the temporal discomfort judgments were also strongly affected by the phase spectra of the flicker, with fixed vs. random spectra producing very different responses. This was not due to the perceived regularity or predictability of the flicker, but could arise from a number of other potential factors. Our findings suggest that, like spatial patterns, visual discomfort in time-varying patterns depends in part on how similar they are to the amplitude spectra of temporal variations in the natural visual environment, but also point to the critical role of the phase spectrum in the perceived discomfort of flicker.

Accuracy of a Rapid and Non-Invasive Method for the Assessment of Small Fiber Neuropathy Based on Measurement of Electrochemical Skin Conductances.

Peripheral nerves (PN) consist of small and large fibers (1). The small fibers represent 80% of PN and are long, thin, with little or no myelin. They are, therefore, more fragile and the first to be damaged in many pathological processes (2–5). The current clinical diagnostic methods mainly assess large fibers (6). Similarly the gold standard neurophysiological tool, namely nerve conduction studies or NCS, is also limited to measuring large fiber function. These recommended methodologies, therefore, only examine 20% of PN, those that are largest and degenerate late or not at all in certain diseases. Small fibers can be sensory or autonomic and there are several methods to assess small fiber function or structure (7). Laser-evoked potentials assess A-delta fiber function (sensory nerves) but these instruments are not widely available (8). Quantitative sensory testing (QST) measures sensitivity to cold, heat, and vibration (sensory small and large fibers) and is more widely available but time-consuming and subjective for routine clinical practice (9). Skin biopsies can assess small fiber structure but are relatively invasive (3 mm in diameter, 1 month for full healing) and, thus, are ill suited for longitudinal assessments (10). Sudomotor function assessing small fibers of the sympathetic autonomic system can be evaluated by the quantitative sudomotor axon reflex test (QSART); though considered the reference method, QSART remains mostly limited to research centers due to the technical complexity and relative discomfort of the examination (11). Other sudomotor methodologies include the Neuropad, which is semi-quantitative and not highly sensitive (12), quantitative direct and indirect testing (QDIRT) and the dynamic sweat test (DST). QDIRT and DST both induce sweating with iontophoresis of acetylcholine or pilocarpine; they are relatively tedious and not particularly suited to the outpatient clinic and there are no data validating the diagnostic utility of these newer technologies (13, 14). Specific stains can be used to evaluate sweat gland nerve fiber density (SGNFD), but there is currently no standardized methodology or normative reference ranges for SGNFD (15). The SUDOSCAN® device was developed to allow the quantitative measurement of sweat gland function using a simple and rapid process (16, 17). Results are immediately available and expressed as electrochemical skin conductances (ESCs). This technique has been compared to reference neurological tests, is not operator dependent, and could be used in the follow-up of patients and in multi-center studies (18–21). The aim of this study was to assess repeatability and reproducibility of the method in healthy volunteers (HV) and diabetic patients with a range of glycemic control.

Using Projected Light for Mobile Remote Guidance

A worker performing a physical task may need to ask for advice and guidance from an expert. This can be a problem if the expert is in some distant location. In this paper, we describe a system which allows the expert to see the workplace from the worker's point of view, and to draw annotations directly into that workplace using a pico-projector. Since the system can be worn by the worker, these projected annotations may move with the worker's movements. We describe a method for sticking these annotations to the original positions thereby compensating for the movement of the worker. We call this `StickyLight'. We conducted a user study to evaluate the performance and user preference for the system in `sticky' and freehand (`non-sticky') modes. We also compared the system on two platforms: helmet mounted and tripod mounted. Results indicate that freehand conditions took less time than sticky, and that tripod conditions took less time than helmet. However, participants reported preferences for sticky over non-sticky, likely due to the relative discomfort of keeping the helmet steady. This echoes the findings of several recent similar investigations..

The relative discomfort of noise and vibration: effects of stimulus duration

How noise discomfort and vibration discomfort depend on duration has not previously been compared. For five durations (2, 4, 8, 16 and 32 s), the subjective equivalence of noise and vibration was investigated with all 49 combinations of 7 levels of noise and 7 magnitudes of whole-body vertical vibration. The rates of increase in discomfort with increasing duration were similar for noise and vibration, whereas they are currently assumed to be 3 dB per doubling of noise duration and 1.5 dB per doubling of vibration duration. The discomfort caused by low levels of noise was masked by high magnitudes of vibration, and the discomfort caused by low magnitudes of vibration was masked by high levels of noise. As stimuli durations increased from 2 to 32 s, the influence of vibration on the judgement of noise discomfort decreased, whereas the influence of noise on the judgement of vibration discomfort was unchanged.

The application of SEAT values for predicting how compliant seats with backrests influence vibration discomfort

The extent to which a seat can provide useful attenuation of vehicle vibration depends on three factors: the characteristics of the vehicle motion, the vibration transmissibility of the seat, and the sensitivity of the body to vibration. The ‘seat effective amplitude transmissibility’ (i.e., SEAT value) reflects how these three factors vary with the frequency and the direction of vibration so as to predict the vibration isolation efficiency of a seat. The SEAT value is mostly used to select seat cushions or seat suspensions based on the transmission of vertical vibration to the principal supporting surface of a seat. This study investigated the accuracy of SEAT values in predicting how seats with backrests influence the discomfort caused by multiple-input vibration. Twelve male subjects participated in a four-part experiment to determine equivalent comfort contours, the relative discomfort, the location of discomfort, and seat transmissibility with three foam seats and a rigid reference seat at 14 frequencies of vibration in the range 1–20 Hz at magnitudes of vibration from 0.2 to 1.6 ms−2 r.m.s. The ‘measured seat dynamic discomfort’ (MSDD) was calculated for each foam seat from the ratio of the vibration acceleration required to cause similar discomfort with the foam seat and with the rigid reference seat. Using the frequency weightings in current standards, the SEAT values of each seat were calculated from the ratio of overall ride values with the foam seat to the overall ride values with the rigid reference seat, and compared to the corresponding MSDD at each frequency. The SEAT values provided good predictions of how the foam seats increased vibration discomfort at frequencies around the 4-Hz resonance but reduced vibration discomfort at frequencies greater than about 6.3 Hz, with discrepancies explained by a known limitation of the frequency weightings.

Evaluating the potential risk of musculoskeletal disorders among bakers according to LUBA and ACGIH-HAL indices

Received: August 2015, Accepted: September 2015 Background: Bakers, due to the nature of their jobs, are at risk of musculoskeletal disorders (MSDs) caused by ergonomic factors. The purpose of this study was to evaluate the biomechanical risk factors for MSDs in bakers. Materials and Methods: In the current study, all Sangak, Taftoon, and Lavash bread bakeries in Gonabad, Iran, were selected based on census method. Then, hierarchical task analysis (HTA) method was used for task analysis and their occupation was classified into tasks, actions, and movements. The Shater (the employee who places the bread in the oven), Chanegeer (the employee who cuts the dough), and Nangeer (the employee who removes the bread from the oven) employees were studied in this respect. Subsequently,postural loading on the upper body assessment (LUBA) and American Conference of Governmental Industrial Hygienists-Hand activity level (ACGIH-HAL) methods were implemented to identify common risk factors in repetitive tasks that can contribute to the development of MSDs of upper limbs. Analysis of the results in this study was performed using SPSS software. Results: A LUBA score of higher than 10 was obtained by 83.33% of workers in Tafton bakeries, 100% of employees in Sangak bakeries, and 91.66% of workers inLavash bakeries. ACGIH-HAL index results of 100% of Sangak, 50.37% of Taftoon, and 50% of Lavash bakery workers were in the red (danger) zone. The LUBA score of nosubjects was below 5 (action level one).Highest relative discomfort score of Nangeer and Shater in Tafton bakeries was in the back area and of Chanegeer in the neck and shoulder area. Highest score of relative discomfort of Shater, Chanegeer, and Nangeeremployees of Lavash bakerieswas in the lumbar area and neck and ofShater and Nangeer of Sangak bakerieswas in the elbow and wrist area. Conclusions: The results showed that the risk of MSDs due to repetitive tasks is relatively high in bakeryand ergonomic interventions required in order to redesign the job.

Comparative Assessment of Cerebral Hemodynamics in School-Age Children Living in the Far Eastern and European North

Cerebral hemodynamics were studied in northern schoolchildren aged 7–17 years living in the absolute (Magadan Region, 62°N, n = 167) and relative (Arkhangelsk Region, 61°N, n = 52) discomfort zones by transcranial Doppler sonography and rheoencephalography. New data were obtained on measures of blood flow in the main cerebral arteries, vessel tone, vasomotor reactivity, and the development of these values in children in two northern regions of the Russian Federation. Blood flow rates in the cerebral arteries of Evens and Koryaks, who form the aboriginal population, were significantly greater than in children of incoming settlers. There was a tendency to an increase in the tone of resistance vessels in northern children, which was more marked among children living in the harsher conditions of the Magadan Region. Parameters characterizing individual adaptive rearrangements of cerebral circulation and the features possibly associated with the formation of the “polar metabolic type” are discussed.

The effects of sound level and vibration magnitude on the relative discomfort of noise and vibration

The relative discomfort caused by noise and vibration, how this depends on the level of noise and the magnitude of vibration, and whether the noise and vibration are presented simultaneously or sequentially has been investigated in a laboratory study with 20 subjects. Noise and vertical vibration were reproduced with all 49 combinations of 7 levels of noise and 7 magnitudes of vibration to allow the discomfort caused by one of the stimuli to be judged relative to the other stimulus using magnitude estimation. In four sessions, subjects judged noise relative to vibration and vibration relative to noise, with both simultaneous and sequential presentations of the stimuli. The equivalence of noise and vibration was not greatly dependent on whether the stimuli were simultaneous or sequential, but highly dependent on whether noise was judged relative to vibration or vibration was judged relative to noise. When judging noise, higher magnitude vibrations appeared to mask the discomfort caused by low levels of noise. When judging vibration, higher level noises appeared to mask the discomfort caused by low magnitudes of vibration. The judgment of vibration discomfort was more influenced by noise than the judgment of noise discomfort was influenced by vibration.