Impulsive sound can be perceived more annoying than a steady-state sound having the same A-weighted equivalent sound pressure level, LAeq. The difference in perceived noise annoyance can be ...compensated by adding a penalty or an adjustment k to LAeq (rating level). Many legislations apply a constant penalty value, such as 5 dB or more, but the validity of this procedure has been questioned. Nordtest method NT ACOU 112 identifies an impulse from the time profile of sound pressure level by using two measures describing the onset of an impulse: level difference (DL) and onset rate (Ron). The purpose of this study was to determine how the annoyance penalty depends on DL (5–40 dB) and Ron (5–800 dB/s) and to compare obtained results to the penalty prediction model of Nordtest method. A psychoacoustic laboratory experiment of 32 participants was conducted. Synthetic and periodic impulsive sounds were studied with two alternative spectra. The sounds were presented at 55 dB LAeq. Steady-state sounds at levels 49–70 dB were used to derive the penalty of impulsive sounds. The observed penalty values ranged between 0 and + 8 dB. The penalty values depended somewhat on spectrum. The penalty deviated from zero when DL > 10 dB or Ron > 15 dB/s and increased with increasing DL and Ron. The penalty predicted by Nordtest method usually overestimated the observed penalty when Ron ≥ 200 dB/s. The results are against constant penalty values and they can be used to develop future penalty schemes.
•Impulsive noise is more annoying than steady-state noise and deserves a penalty.•Our results were against constant penalty values used in most noise regulations.•Penalty values ranged from 0 to 8 dB depending on the prominence of the impulse.•Prominence depends on impulse envelope: onset rate and level difference.•Results can be used to assess the annoyance of impulsive noise in buildings.
Effects of noise on people depend on sound level but also on other sound properties. A systematic comparison of the stress effects of speech and noise with the same frequency content is missing. This ...study compared stress reactions under sound conditions speech (sound level 65 dB LAeq), noise (65 dB), and silence (35 dB), all having similar relative frequency contents. Fifty‐nine participants were exposed to one out of three sound conditions on average for 48 minutes while performing tasks requiring concentration. Acute physiological stress was estimated by measuring stress hormone concentrations in plasma (cortisol and noradrenaline), heart rate variability (HRV), and blood pressure. Psychological stress measures were subjective noise annoyance, workload, and fatigue. Compared to silence and noise, working during speech was more annoying, loading, but less tiring, and led to elevated HRV LF/HF ratio with time. Speech also raised cortisol levels compared with silence. Although noise was more annoying, and raised cortisol levels compared with silence, working during speech was more loading and caused more physiological stress than other sound conditions. Special care should be paid to noise control in workplaces requiring concentration because already exposure to moderate sound level sounds caused clear physiological effects on people.
•This is the first study exploring both loudness and annoyance of infrasound.•Infrasound is not inaudible: all participants heard it, if the level was sufficient.•Other sensations except hearing were ...not restricted to infrasound range.•Infrasound seems not to differ from non-infrasound regarding basic perceptions.
Research related to perception, loudness, and annoyance of infrasound (frequency below 20 Hz) is limited compared to non-infrasound (20–20000 Hz). The purpose was to determine hearing threshold, equal loudness contours, equal annoyance contours, and other sensations apart from hearing. The laboratory experiment involved 19 normal hearing participants. Observed hearing thresholds within 4–8000 Hz agreed with previous findings supporting the adequacy of our methods. Equal-loudness contours for 20, 40, and 60 phon were determined within 4–1000 Hz. They emphasized the non-linear nature of hearing. The dynamic range of hearing is extremely suppressed at infrasonic frequencies: an increment of 5 dB at 4 Hz feels like an increment of 10 dB at 20 Hz and an increment of 20 dB at 1 kHz. Equal-annoyance contours were derived for 20, 40, and 50 phon within 4–1000 Hz. Because individual hearing thresholds varied up to 20 dB, an infrasonic tone still being inaudible for one participant could be loud or annoying for another participant. The finding may explain why some people perceive low frequency sound more annoying than the others. Other sensations apart from hearing (such as pressure in the ear, headache, and vibration sensation) were reported both for infrasound and non-infrasound. Thus, other sensations apart from hearing are not limited to infrasonic frequencies. The study findings emphasize that sound below 20 Hz should be treated similarly as sounds within 20–20000 Hz. Health effect assessment procedures would benefit from standardized hearing threshold below 20 Hz.
Impulsive sound has been found to annoy people more than steady-state sound or many other types of sound presented at the same sound level. This study examined the physiological, performance, and ...subjective effects of impulsive sound on working humans. Exposure to impulsive sound (65 dB LAeq) was compared with quiet sound (35 dB LAeq) and steady-state sound (65 dB LAeq). This parallel-group study, where each participant was exposed to one sound condition, had altogether 59 participants. Physiological stress was measured with stress hormone concentrations in plasma (cortisol and noradrenaline), heart rate variability (HRV), and blood pressure. Psychological stress was measured with subjective noise annoyance, workload, and fatigue. Performance was measured in tasks requiring constant concentration (visual and auditory serial recall and N-back). Compared to quiet sound, impulsive sound caused more annoyance, workload, and lack of energy, raised cortisol concentrations, reduced systolic blood pressure, and decreased accuracy in the 3-back task. Compared with steady-state sound, impulsive sound was experienced as more annoying and causing a higher workload and more lack of energy. Impulsive sound caused physiological and psychological stress and decreased performance compared to quiet sound. Part of this load was due to the increased sound level, which was evident as a physiological stress reaction. Still, there was also an extra stress effect related to the impulsiveness of the sound, reflected as a psychological experience. Special care should be paid to impulsive sound, especially in environments where people are performing mental work.
•We examined the effect of impulsive sound on humans during mental work.•Participants were exposed to impulsive sound, steady-state sound, and quiet sound.•Impulsive sound caused higher stress and lower performance than quiet sound.•Steady-state sound elevated physiological stress response compared to quiet sound.•Working during impulsive sound was more demanding than during steady-state sound.
Irrelevant speech impairs cognitive performance, especially in tasks requiring verbal short-term memory. Working on these tasks during irrelevant speech can also cause a physiological stress ...reaction. The aim of this study was to examine heart rate variability (HRV) as a non-invasive and easy-to-use stress measure in an irrelevant speech paradigm. Thirty participants performed cognitive tasks (n-back and serial recall) during two sound conditions: irrelevant speech (50 dB) and quiet (33 dB steady-state noise). The influence of conditions as well as presentation orders of conditions were examined on performance, subjective experience, and physiological stress. Working during irrelevant speech compared to working during quiet reduced performance, namely accuracy, in the serial recall task. It was more annoying, heightened the perceived workload, and lowered acoustic satisfaction. It was related to higher physiological stress by causing faster heart rate and changes in HRV frequency-domain analysis (LF, HF and LF/HF). The order of conditions showed some additional effects. When speech was the first condition, 3-back performance was less accurate, and serial recall response times were longer, heart rate was faster, and successive heart beats had less variability (lower RMSSD) during speech than during quiet. When quiet was the first condition, heart rate was faster and reaction times in 3-back were slower during quiet than during speech. The negative effect of irrelevant speech was clear in experience, performance, and physiological stress. The study shows that HRV can be used as a physiological stress measure in irrelevant speech studies.
•Does task irrelevant speech cause stress visible in heart rate variability?•The effects of working during speech were compared to working during quiet.•Heart rate variability indicated higher stress during speech than during quiet.•If speech was the first condition, some transient additional effects were visible.
•Experiences recalled after responsive and unresponsive sedation were assessed.•Equipotent doses of dexmedetomidine, propofol, sevoflurane, and S-ketamine were used.•46.9% of arousable participants ...reported disconnected experiences after sedation.•Responsiveness did not affect the prevalence or content of reported experiences.•Unresponsiveness during anesthetic administration does not denote unconsciousness.
To understand how anesthetics with different molecular mechanisms affect consciousness, we explored subjective experiences recalled after responsive and unresponsive sedation induced with equisedative doses of dexmedetomidine, propofol, sevoflurane, and S-ketamine in healthy male participants (N = 140). The anesthetics were administered in experimental setting using target-controlled infusion or vapouriser for one hour. Interviews conducted after anesthetic administration revealed that 46.9% (n = 46) of arousable participants (n = 98) reported experiences, most frequently dreaming or memory incorporation of the setting. Participants receiving dexmedetomidine reported experiences most often while S-ketamine induced the most multimodal experiences. Responsiveness at the end of anesthetic administration did not affect the prevalence or content of reported experiences. These results demonstrate that subjective experiences during responsive and unresponsive sedation are common and anesthetic agents with different molecular mechanisms of action may have different effects on the prevalence and complexity of the experiences, albeit in the present sample the differences between drugs were minute.
Tiivistelmä. Selvitin tutkimuksessani, miten improvisaatioteatteri voi vaikuttaa kulttuuriseen ja sosiaaliseen integraatioprosessiin. Tein tutkimukseni Tanskassa Kööpenhaminan kaupungissa ...sijaitsevassa ICC-teatterissa (Improv Comedy Copenhagen). ICC-teatteri on improvisaatioteatteri, joka järjestää esityksiä sekä teatteritaiteeseen liittyviä kursseja niin yksityisille henkilöille kuin yrityksille ja instituutioille.
Tutkimukseni kohde olivat ICC-teatterin näyttelijät yksityisillä kursseilla. Kursseihin osallistui noin 10-15 henkilöä ja yksi kurssi kesti noin 6 viikkoa. Suurin osa näyttelijöistä näillä kursseilla oli maahanmuuttajia ympäri maailmaa. Niissä ryhmissä joita minä tutkin, maahanmuuttajat olivat poikkeuksetta muuttaneet Tanskaan työn tai koulutuksen perässä. Tein osallistuvaa havainnointia kolmessa eri ryhmässä. Yhdessä näistä ryhmästä oli itse mukana aktiivisesti näyttelijänä, kun taas kahdessa muussa ryhmässä toimin ikään kuin sivustaseuraajana. Tein myös haastatteluita 6 eri näyttelijän kanssa. Sain jokaisesta ryhmästä kaksi näyttelijää haastateltavaksi. Suurin osa kirjallisista lähteistäni olivat englanninkielisiä, joka edellytti minulta siis paljon kääntämistä. Loput kirjallisuudesta olivat suomenkielistä.
Olennaisia asiasanoja tutkimuksessani ovat improvisaatioteatteri sekä sosiaalinen ja kulttuurinen integraatioprosessi. Sovelsin tutkimuksessani kongnitiivistä antropologiaa ja kultturimalliteoriaa. Tutkimukseni tarkoitus on selvittää, miten improvisaatioteatteri vaikuttaa sosiaaliseen ja kulttuuriseen integraatioprosessiin.
Improvisaatioteatteri merkitsi näyttelijöille pääsääntöisesti hauskaa ajanviettopaikkaa. Teatterissa tehtiin monenlaisia harjoituksia, mutta jokaista harjoitusta yhdisti samanlainen tavoite - yhdessä työskentely ja toisten auttaminen. Johtuen tästä yhteenkuuluvuuden tunteesta, improvisaatioteatterilla voi olla vaikutus sosiaaliseen ja kulttuuriseen integraatioprosessiin. Näyttelijöiden tapa toimia yhdessä ja matkia toisia näyttelijöitä toivat ilmi sosiaalisen ja kulttuurisen integraatioprosessin improvisaatioteatterin tekemisessä. Tutkimassani ICC-teatterissa näyttelijöitä ei pyritty tietoisesti integroimaan mihinkään kulttuuriin, mutta improvisaatioteatterissa tapahtunut toiminta ja sen puitteet mahdollistivat integraation näyttelijöiden oman integraatioon liittyvän kulttuurisen mallin mukaisesti.
Some bacterial strains such as Komagataeibacter xylinus are able to produce cellulose as an extracellular matrix. In comparison to wood-based cellulose, bacterial cellulose (BC) holds interesting ...properties such as biodegradability, high purity, water-holding capacity, and superior mechanical and structural properties. Aiming toward improvement in BC production titer and tailored alterations to the BC film, we engineered K. xylinus to overexpress partial and complete bacterial cellulose synthase operon that encodes activities for BC production. The changes in cell growth, end metabolite, and BC production titers from the engineered strains were compared with the wild-type K. xylinus. Although there were no significant differences between the growth of wild-type and engineered strains, the engineered K. xylinus strains demonstrated faster BC production, generating 2–4-fold higher production titer (the highest observed titer was obtained with K. xylinus-bcsABCD strain producing 4.3 ± 0.46 g/L BC in 4 days). The mechanical and structural characteristics of cellulose produced from the wild-type and engineered K. xylinus strains were analyzed with a stylus profilometer, in-house built tensile strength measurement system, a scanning electron microscope, and an X-ray diffractometer. Results from the profilometer indicated that the engineered K. xylinus strains produced thicker BC films (wild type, 5.1 μm, and engineered K. xylinus strains, 6.2–10.2 μm). Scanning electron microscope revealed no principal differences in the structure of the different type BC films. The crystallinity index of all films was high (from 88.6 to 97.5%). All BC films showed significant piezoelectric response (5.0–20 pC/N), indicating BC as a promising sensor material.
This paper explores the synchronized change of mindset and capability within a business network that is driven by the adoption and provision of smart services. The research is implemented as an ...empirical multi‐case study, and the primary data include interviews and observations in seven globally operating firms. The findings identify two categories of barriers and three categories of alignment needs to successful adoption of smart services. The study combines the institutional theory and dynamic capability perspectives to make three main contributions to the research of service innovation for an improved understanding of the determinants of successful field‐level adoption of smart services. The results show that firms need to align the change of logic and capabilities within the organization and the business network to succeed in the adoption of smart services.
dyadic cubes adapting ultrametric structure. If the space is complete, then the existence of such cubes and the mass distribution principle lead into a simple proof for the existence of doubling ...measures. As an application, we show that for each \varepsilon >>.>
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