C.N. van der Wal
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11 records found
1
Hospital Soundscapes
Integrating Psychoacoustics and ISO 12913-based Perceptual Assessment for Departmental Profiling and Evidence-based Interventions
This thesis examines the acoustic environments of four clinical departments — Emergency, Intensive Care Unit, Oncology, and Haematology — across four Dutch hospitals. Its central argument is that hospital sound cannot be adequately understood through decibels alone. The study proposes and demonstrates an integrated approach that combines psychoacoustic metrics derived from the Zwicker model with ISO 12913-based perception surveys, to characterise not only how loud a department is, but how it is perceived.
Data were collected through 124 calibrated acoustic measurements and 86 in-situ perception surveys, administered simultaneously to staff and patients, enabling direct pairing of objective and subjective datasets. The findings show that hospital departments differ not only in volume but in acoustic profile. The Emergency department recorded the highest values across every dimension measured and was perceived as chaotic and acoustically inappropriate. Haematology achieved the quietest and most acoustically favourable profile, an outcome attributable to private room enclosure and soft-close hardware rather than reduced staffing or patient activity. The Intensive Care Unit and Oncology occupied intermediate positions with distinctly different acoustic characters: the ICU registered lower mean annoyance overall yet was perceived as persistently harsh, owing to the tonal character of monitoring alarms reflected in the highest tonality values of any department; Oncology carried a higher mean annoyance distributed more evenly across equipment and environmental sources, rendering it perceptually more tolerable in quality despite the comparable sound level.
The strongest statistical relationship identified is between equivalent sound level and perceived appropriateness, with a Spearman correlation of -0.94, p < 0.01. This finding reinforces the core argument: in clinical environments, how appropriate a soundscape feels is more strongly predicted by its acoustic character than by its level.
The ISO 12913 framework demonstrated diagnostic utility, separating departments on the soundscape circumplex and integrating objective with perceptual data. Method A proved feasible in active clinical settings. Three adaptations are identified as necessary for hospital research specifically: a proxy or observational pathway for patients unable to complete the perception questionnaire; longitudinal sampling in place of single-session surveys, since hospital acoustic exposure is sustained rather than momentary; and explicit treatment of clinical role as a perceptual moderator rather than untreated background context.
The thesis translates these findings into department-specific intervention priorities and a business case linking acoustic quality to patient experience, staff retention, alarm safety, and clinical recovery. The evidence points toward a model of soundscape-informed design in which psychoacoustic profiling, alongside conventional noise measurement, becomes a standard component of hospital acoustic assessment.
Hospitals will never be silent. Nor should they be. ...
This thesis examines the acoustic environments of four clinical departments — Emergency, Intensive Care Unit, Oncology, and Haematology — across four Dutch hospitals. Its central argument is that hospital sound cannot be adequately understood through decibels alone. The study proposes and demonstrates an integrated approach that combines psychoacoustic metrics derived from the Zwicker model with ISO 12913-based perception surveys, to characterise not only how loud a department is, but how it is perceived.
Data were collected through 124 calibrated acoustic measurements and 86 in-situ perception surveys, administered simultaneously to staff and patients, enabling direct pairing of objective and subjective datasets. The findings show that hospital departments differ not only in volume but in acoustic profile. The Emergency department recorded the highest values across every dimension measured and was perceived as chaotic and acoustically inappropriate. Haematology achieved the quietest and most acoustically favourable profile, an outcome attributable to private room enclosure and soft-close hardware rather than reduced staffing or patient activity. The Intensive Care Unit and Oncology occupied intermediate positions with distinctly different acoustic characters: the ICU registered lower mean annoyance overall yet was perceived as persistently harsh, owing to the tonal character of monitoring alarms reflected in the highest tonality values of any department; Oncology carried a higher mean annoyance distributed more evenly across equipment and environmental sources, rendering it perceptually more tolerable in quality despite the comparable sound level.
The strongest statistical relationship identified is between equivalent sound level and perceived appropriateness, with a Spearman correlation of -0.94, p < 0.01. This finding reinforces the core argument: in clinical environments, how appropriate a soundscape feels is more strongly predicted by its acoustic character than by its level.
The ISO 12913 framework demonstrated diagnostic utility, separating departments on the soundscape circumplex and integrating objective with perceptual data. Method A proved feasible in active clinical settings. Three adaptations are identified as necessary for hospital research specifically: a proxy or observational pathway for patients unable to complete the perception questionnaire; longitudinal sampling in place of single-session surveys, since hospital acoustic exposure is sustained rather than momentary; and explicit treatment of clinical role as a perceptual moderator rather than untreated background context.
The thesis translates these findings into department-specific intervention priorities and a business case linking acoustic quality to patient experience, staff retention, alarm safety, and clinical recovery. The evidence points toward a model of soundscape-informed design in which psychoacoustic profiling, alongside conventional noise measurement, becomes a standard component of hospital acoustic assessment.
Hospitals will never be silent. Nor should they be.
Behind the Meter: End-User Flexibility for Congestion Mitigation
An Agent-Based Exploration of Residential Behavior and Measures for Low-Voltage Congestion Relief
This thesis uses an Agent-Based Model to simulate five household profiles (Conscientious Individuals, Structure Seekers, Status-Driven, Responsibles, and Self-Developers) and their participation in three flexibility measures: smart EV charging, solar PV curtailment, and flexible heat pump control. Awareness campaigns are included as a soft intervention. Profiles and parameters were informed by literature and interviews with Dutch DSOs. Scenarios reflect current conditions and two future policy paths, including the planned abolition of net metering.
Results show large differences in participation across profiles. Conscientious Individuals and Responsibles adopt early, while Status-Driven households are least likely to engage. Summer feed-in peaks can be fully mitigated in ideal conditions, but reducing winter peaks proves more difficult due to limited uptake of heat pump flexibility.
The study shows that behavioral segmentation adds critical value to energy modeling. Targeted engagement strategies based on user profiles can help DSOs design more effective, inclusive flexibility programs, aligning grid stability efforts with real-world household behavior. ...
This thesis uses an Agent-Based Model to simulate five household profiles (Conscientious Individuals, Structure Seekers, Status-Driven, Responsibles, and Self-Developers) and their participation in three flexibility measures: smart EV charging, solar PV curtailment, and flexible heat pump control. Awareness campaigns are included as a soft intervention. Profiles and parameters were informed by literature and interviews with Dutch DSOs. Scenarios reflect current conditions and two future policy paths, including the planned abolition of net metering.
Results show large differences in participation across profiles. Conscientious Individuals and Responsibles adopt early, while Status-Driven households are least likely to engage. Summer feed-in peaks can be fully mitigated in ideal conditions, but reducing winter peaks proves more difficult due to limited uptake of heat pump flexibility.
The study shows that behavioral segmentation adds critical value to energy modeling. Targeted engagement strategies based on user profiles can help DSOs design more effective, inclusive flexibility programs, aligning grid stability efforts with real-world household behavior.
To explore this, an agent-based simulation model was developed using NetLogo. The model simulates evacuation scenarios in two structurally different campus buildings at TU Delft: the Applied Sciences building and the Civil Engineering & Geosciences building. The key variables studied were familiarity with the building layout and exits, social influence behaviour, egress width, and signage. Evacuation performance was assessed using three metrics: 75% evacuation time, mean density, and exit choice.
Following a full factorial simulation experiment of 54 different scenarios per building totalling 10800 individual runs, a standardised ranking was created to equitably rank the scenarios based on their relative evacuation time, density, and exit choice, to determine the performance of the factors. A general linear model was created to determine the effect size of both the individual factors and all possible interactions.
The simulation results demonstrate that familiarity and egress width had the most significant impact on evacuation efficiency. In buildings with limited exits, egress width outweighed the effect of familiarity. While signage and social influence showed modest or statistically non-significant impacts overall, signage became more effective in low-familiarity contexts. The effect of social influence appeared to be sensitive to its level of formalisation in the model, underscoring its context-dependent nature.
Strengths of this study lie in the multi-metric perspective on evacuation performance, the use of multiple buildings to test effects in different structural environments, the possibility to include all possible interactions through a full factorial design, and the adaptability of the simulation model. Also, this study has several limitations, namely the balance between model correctness and performance, the difficulty to detect behavioural patterns, and software-based limitations.
From a policy perspective, the findings suggest that improving occupant familiarity with building layouts, through orientation, drills, or signage, can substantially improve evacuation performance. Furthermore, structural adjustments such as widening exits can mitigate congestion in critical zones, although its effect is dependent on hallway width. Although advanced signage technologies offer some improvements, their individual effectiveness is limited without complementary strategies.
The study highlights the importance of addressing evacuation preparedness as a multi-factorial challenge, especially in complex university settings where population heterogeneity and architectural diversity intersect. The model and methodology offer a flexible tool for future research and scenario testing. ...
To explore this, an agent-based simulation model was developed using NetLogo. The model simulates evacuation scenarios in two structurally different campus buildings at TU Delft: the Applied Sciences building and the Civil Engineering & Geosciences building. The key variables studied were familiarity with the building layout and exits, social influence behaviour, egress width, and signage. Evacuation performance was assessed using three metrics: 75% evacuation time, mean density, and exit choice.
Following a full factorial simulation experiment of 54 different scenarios per building totalling 10800 individual runs, a standardised ranking was created to equitably rank the scenarios based on their relative evacuation time, density, and exit choice, to determine the performance of the factors. A general linear model was created to determine the effect size of both the individual factors and all possible interactions.
The simulation results demonstrate that familiarity and egress width had the most significant impact on evacuation efficiency. In buildings with limited exits, egress width outweighed the effect of familiarity. While signage and social influence showed modest or statistically non-significant impacts overall, signage became more effective in low-familiarity contexts. The effect of social influence appeared to be sensitive to its level of formalisation in the model, underscoring its context-dependent nature.
Strengths of this study lie in the multi-metric perspective on evacuation performance, the use of multiple buildings to test effects in different structural environments, the possibility to include all possible interactions through a full factorial design, and the adaptability of the simulation model. Also, this study has several limitations, namely the balance between model correctness and performance, the difficulty to detect behavioural patterns, and software-based limitations.
From a policy perspective, the findings suggest that improving occupant familiarity with building layouts, through orientation, drills, or signage, can substantially improve evacuation performance. Furthermore, structural adjustments such as widening exits can mitigate congestion in critical zones, although its effect is dependent on hallway width. Although advanced signage technologies offer some improvements, their individual effectiveness is limited without complementary strategies.
The study highlights the importance of addressing evacuation preparedness as a multi-factorial challenge, especially in complex university settings where population heterogeneity and architectural diversity intersect. The model and methodology offer a flexible tool for future research and scenario testing.
Impact of leader-follower behavior on evacuation performance
An exploratory modeling approach
Trafficking and Trust
Understanding the role of trust in a criminal supply chain
Computational decision support for crowd management applications
A case study on operational in-event pedestrian crowd management
The Role Of The EU In Encouraging Sustainable Protein Consumption
An Agent-Based Model On The Effect Of Social Norms On Reducing Meat Consumption in the Netherlands
Understanding group behaviour during evacuations inside buildings
An exploratory agent-based modelling approach
Determining effective evacuation strategies based on WiFi data in Buildings
An exploratory data-driven and agent-based evacuation modeling approach
The influence of national culture on response behaviour during an evacuation
An agent-based approach
Evacuation behaviour consists of two phases: the response phase and the evacuation movement phase. During the response phase, a building occupant is notified of an incident and performs a series of information and action tasks. When the response phase is finished, a building occupant will initiate movement towards an exit or safe place during the evacuation movement phase.
In this thesis, the focus is on response-phase behaviour. There are many factors influencing response-phase behaviour, four of these are: culture, cues, affiliation and setting.
Culture is defined as "the collective programming of the mind distinguishing the members of one group or category of people from others". For this research, national cultures have been considered.
Cues are any kind of changes in the environment, which indicate that something is not normal. Affiliation encompasses the tendency for people to seek friends or colleagues. Lastly, setting limits the knowledge obtained and the type of actions which can be performed based on the location of the building occupant.
The following research question has been answered: " How does culture, in combination with cues, settings and affiliation, influence response-phase behaviour and time and total evacuation time ? ”. To answer the research question, a case study was introduced. In this case study library evacuations have been considered in Czech Republic, Poland, Turkey and the UK. Within the context of this case study a questionnaire and an agent-based model have been developed.
The results show that that there are significant differences in the number of response tasks being performed. Turkey performs the highest number of response tasks, followed in a decreasing order by Poland, Czech Republic and the UK. Furthermore, it has been found that response behaviour in all countries is influenced by cues, setting and affiliation, which results in significant differences between the countries for their response and evacuation time. It has been found that, as with the number of response tasks, Turkey has the highest evacuation and response times, followed in a decreasing order by Poland, Czech Republic and the UK. Lastly, it has been found that affiliation and being informed by a staff member highly affect response and evacuation times, while the setting and seeing fire do not. The degrees to which these factors influence response and evacuation times differ per country.
Overall, this research acknowledges the importance of performing cross-cultural research for evacuation behaviour. It has shown the need for policy makers and emergency planners to discuss effects of culture on evacuations. Additionally, it provides a new approach to study the effect of cultures, in combination with cues, setting and affiliation, on response-phase behaviour and response and evacuation times.
...
Evacuation behaviour consists of two phases: the response phase and the evacuation movement phase. During the response phase, a building occupant is notified of an incident and performs a series of information and action tasks. When the response phase is finished, a building occupant will initiate movement towards an exit or safe place during the evacuation movement phase.
In this thesis, the focus is on response-phase behaviour. There are many factors influencing response-phase behaviour, four of these are: culture, cues, affiliation and setting.
Culture is defined as "the collective programming of the mind distinguishing the members of one group or category of people from others". For this research, national cultures have been considered.
Cues are any kind of changes in the environment, which indicate that something is not normal. Affiliation encompasses the tendency for people to seek friends or colleagues. Lastly, setting limits the knowledge obtained and the type of actions which can be performed based on the location of the building occupant.
The following research question has been answered: " How does culture, in combination with cues, settings and affiliation, influence response-phase behaviour and time and total evacuation time ? ”. To answer the research question, a case study was introduced. In this case study library evacuations have been considered in Czech Republic, Poland, Turkey and the UK. Within the context of this case study a questionnaire and an agent-based model have been developed.
The results show that that there are significant differences in the number of response tasks being performed. Turkey performs the highest number of response tasks, followed in a decreasing order by Poland, Czech Republic and the UK. Furthermore, it has been found that response behaviour in all countries is influenced by cues, setting and affiliation, which results in significant differences between the countries for their response and evacuation time. It has been found that, as with the number of response tasks, Turkey has the highest evacuation and response times, followed in a decreasing order by Poland, Czech Republic and the UK. Lastly, it has been found that affiliation and being informed by a staff member highly affect response and evacuation times, while the setting and seeing fire do not. The degrees to which these factors influence response and evacuation times differ per country.
Overall, this research acknowledges the importance of performing cross-cultural research for evacuation behaviour. It has shown the need for policy makers and emergency planners to discuss effects of culture on evacuations. Additionally, it provides a new approach to study the effect of cultures, in combination with cues, setting and affiliation, on response-phase behaviour and response and evacuation times.