Selen Okcu

Psychoacoustic assessment of a new aircraft engine fan noise synthesis method

Simulation of aircraft flyover events can facilitate psychoacoustic studies exploring the effects of noise generated by future aircraft designs. The perceived realism of a simulated flyover event may be impacted by the perceived realism of the synthesized fan noise of the aircraft engine. Short-term fluctuations in tonal amplitude and frequency are important cues contributing to that perception of realism, but are not accounted for by predictions based on long-term averages. A new synthesis method has been developed at NASA Langley Research Center to generate realistic aircraft engine fan noise using predicted source noise directivities in combination with short-term fluctuations. In the new method, fluctuations in amplitude and frequency are included based upon analysis of static engine test data. Through psychoacoustic testing, this study assessed perceived effectiveness of the new synthesis method in generating realistic fan noise source. Realism was indirectly assessed by judging the similarity of syn...

The role of physical environment on student health and education in green schools

Abstract The role of physical school environment on student health and education is becoming better understood. A growing body of literature indicates that improved physical environments in schools (e.g., indoor air quality, lighting, and acoustic conditions) can enhance student health outcomes. In parallel, the green building movement centers around designing buildings, including schools, that are more sustainable to decrease energy consumption, minimize environmental impact, and create healthier spaces for occupants. This paper synthesizes the findings from both green design studies and school outcomes studies to provide a systematic evaluation of the potential impacts of green school design features on student health outcomes. Three inter-related topics are covered in detail: (i) overview of the “green” concept, including existing guidelines for “greening” schools, attitudes toward green schools, and condition of the physical environments in non-green schools; (ii) potential effects of the physical environment on school children, including documentation of national statistics and summary of findings from school research studies; (iii) synthesis of findings, including a discussion of the knowledge gaps in the field of green school research and conclusions.

Linking acoustics and floor-plate shape qualities of healthcare settings

Nurses do not always have visual access to their patients in hospital corridors. During these times, lack of proper monitoring of auditory cues can potentially delay nurse response time and disable early detection of complications. Particular acoustic characteristics of hospital sound environments such as reverberation time can be highly detrimental to nurses’ sound-based task performance. In previous studies, the effects of surface materials on temporal characteristics of reverberant corridor sound environments have been studied. However, little is known about the relationship between floor-plate shapes and temporal characteristics of reverberant corridor sound environments. The main goal of this study was to statistically examine the relationship between floor-plate shape and temporal characteristics of reverberant sound environments in inter-connected nursing unit corridors by conducting floor-plate shape analysis, acoustic simulation studies and field measurements. Overall, the findings suggest the potential effectiveness of acoustic simulation programs in predicting the temporal characteristics of reverberant sound environments in inter-connected hospital corridors. Based on the acoustic simulation analysis, reverberation time was significantly correlated with two floor-plate shape metrics: visual fragmentation and relative grid distance.

Aural Connectivity: Enhancing sound environments in critical care settings for effective nurse auditory monitoring

In intensive care unit (ICU) settings, the sound environment is critically important to nurses accomplishing their tasks. In earlier studies by the authors, it was found that non‐amplified environmental sounds such as patient bodily sounds, patient threatening/unusual sounds, and help calls from patients and other caregivers are critically important auditory cues that nurses must listen for and respond to immediately. These sounds do not exist in isolation but matter as a pattern of aural connectivity that can support a nurses critical monitoring abilities as she moves through her workplace. Aural connectivity is a network measure that reflects the overall pattern of where users can hear and respond to different key sounds within a setting. This paper describes the sound environments of two ICU hospital settings with similar patient acuity levels but differing layout designs. Preliminary results regarding the patterns of aural connectivity and the role that layout design might play in those patterns are ...

Effects of noise on emergency department staff.

The hospital sound environment is complex. The impact of a poor soundscape is becoming an increasing concern for both staff and patients, particularly in emergency departments (EDs). While there is growing evidence of the negative impacts of a poor soundscape, there is surprisingly little rigorous evidence about exactly what acoustic characteristics impact hospital staff. This paper presents a detailed acoustic study of two EDs in Atlanta, GA. Equivalent sound pressure levels (Leq), speech intelligibility index (SII), spectral distribution, and other acoustic metrics were calculated for four locations in each emergency department over 24 h. Results show Leq’s between 50–63 dBA, which severely exceeds the 30 dBA guideline level set by the World Health Organization. Additionally, no area observed held a “good” SII rating. These acoustic measurements will be compared to results of staff questionnaires focusing on staff stress and job satisfaction. Findings from this work will advance the understanding of how...

Acoustics of interconnected nursing unit corridors.

Nursing units are composed of proportional (e.g., patient room) and nonproportional spaces (e.g., race track and hallway design nursing unit corridors). Acoustic qualities of these spaces can have a significant impact on sound task performance of caregivers such as localization of auditory cues. For example, it is well known that in reverberant environments, the human auditory system‘s ability to localize auditory cues is very limited. Various nonhospital studies documented the acoustic qualities of proportional spaces. However, the number of studies linking the design and acoustics of long enclosures in hospitals is very limited. By conducting acoustic simulation analysis, impulse response measurements, and heuristic design analysis, this study statistically analyzed the link between design and acoustics of interconnected nursing unit corridors.

Hospital soundscape modeling.

Effective soundscape solution considerations for hospital settings can be very complex. Some acoustic qualities of these soundscapes have been shown to have potential negative impacts on occupant outcomes. To enhance these qualities, different acoustic solutions are applied in the hospital settings. Testing the effectiveness of these implications is critical but not always practical in the real settings. In this study, we examined the soundspaces of critical care settings through acoustic models. This paper will discuss the preliminary results regarding the modeled acoustic qualities of various ICU settings such as noise levels and reverb qualities.

Comparing the sound environments in two critical care settings.

Critical care nurses perform crucial tasks in complicated sound environments. The existence of many different noise sources (i.e., staff conversation, medical alarms, etc.) with different sound qualities cause nurses to experience constantly changing acoustic conditions while providing care for critically ill. Some of those acoustical qualities in critical care settings can negatively affect nurse well‐being and task performance. In different critical care settings, the acoustic qualities can vary. Some architectural qualities of those settings can be an indicator of those variations. In this study, we documented the detailed objective and subjective sound environment of two critical care settings with different architectural layouts. The comparative analyses are used to understand the differences between two acoustic settings and the relationship between subjective and objective sound environments. Perceived qualities of the physical work environments are examined to explore the association between archi...

Descriptors of aural connectivity: Architectural enclosure features and acoustical qualities.

In intensive care unit (ICU) settings, auditory monitoring of alarm and nonalarm sounds is one of the key nursing functions. In the ICU sound environments there are many different noise sources, some producing more than one tone to communicate different conditions. In a sound environment with many different sound layers offering different sound qualities and sound levels nurses are expected to distinguish the sounds from each other and identify critical ones. Earlier studies showed that effective auditory monitoring requires recognition, localization, and immediate reaction to critical sounds to improve patient safety, nurse work efficiency, and reduce nurse burnout. This study explores the nurse task specific auditory monitoring experience by documenting the nurse auditory tasks and systematically mapping related sounds. This is analyzed as aural connectivity, a network measure that reflects the overall pattern of where users can recognize and localize the critical sounds in architectural enclosures. It ...