- Basic study on improving sound localisation accuracy for musical tones by adding broadband noise
- 論文掲載日：2017/03/02 第17巻
- Purpose: When presenting a virtual auditory display (VAD) to a user who has difficulty using visual information, such as a visually impaired individual, an acoustic head related transfer function (HRTF) is necessary for vertical localisation. However, measurement of the HRTF is time consuming and costly. Because HRTFs differ between individuals, the use of another person’s HRTF reduces the accuracy of localisation. In this study, we propose and evaluate an extremely simple method for improving the accuracy of virtual sound localisation on the vertical plane using the same HRTF for various individuals, which may help with the use of a VAD.
Subjects and method: Six male university students (mean age of 22.5±2.5 years) with normal hearing and sight participated in the experiment, during which they wore blindfolds. Sound localisation accuracy was compared among three different conditions: presentation of a tone alone (tone condition), presentation of broadband noise alone (noise condition), and mixed presentation of a tone and broadband noise (mixed condition). Two types of playback system were used: a speaker array and virtual conditions (hearing binaurally through headphones). The stimuli were presented from a total of 13 different directions on the median plane at 10° intervals, from -60° (lower side) to 60° (upper side).
Results: As sound sources were presented farther from 0° in either direction, the target direction offset from 0° was more underestimated. It was found that in the virtual condition, the superimposition of musical tones and broadband noise significantly improved localisation accuracy compared with presenting each alone.
Conclusion: The present study demonstrated that when presenting virtual sound without personalising the HRTF, the extremely simple method of adding broadband noise markedly improves sound localisation accuracy on the vertical plane directly ahead of a subject.
Keywords: Virtual Auditory Display, Visual Impairment, Sound Localisation, 3D Sound, Binaural, Augmented Reality.
- Evaluation of anatomical training for nursing students using unfixed lung, trachea, and larynx of swine
- 論文掲載日：2017/01/15 第17巻
- Objectives: Anatomy and physiology are fundamental subjects for establishing a foundation of knowledge for nursing. We have conducted anatomical training using unfixed respiratory internal organs (lung, trachea, and larynx) of swine in order to provide anatomy education to nursing students, since nursing students in Japan are not able to dissect the human body for learning. The objective of this study was to evaluate anatomical training of participating students and instructors, in order to inform development of an educational system effective at teaching anatomy of the respiratory system, and to enhance educational technique.
Subjects and methods:Grade 1 nursing students participated in an anatomy practicum using unfixed respiratory systems of swine (dissection, identification of the parts, labelling, measurement, and recording), after prior study of a textbook and distributed the manual for this anatomical training. We conducted a survey using a questionnaire with five-point Likert scale responses to investigate the benefit of the anatomical training among 425 nursing students who participated in the anatomy practicum. We also interviewed 5 instructors to evaluate the anatomical training.
Conclusions: The percentage of students who evaluated the anatomical training as meaningful were 95.4%, 94.1%, and 88.8% for lung, trachea, and larynx, respectively (average 92.8%). Our results suggest that the anatomical training was meaningful for learning anatomy among nursing students. In particular, many students were interested in the air injection demonstration using unfixed lung and segmental bronchus, where movement of the lung can be clearly observed, providing a strong learning opportunity. This demonstration is one of the most popular training experiences among the students. The demonstration enhances understanding of the concept of the pulmonary segmentation, shrinkage of the lung, and pneumothorax, as well as the dynamic image of change of the lung during respiration.
Keywords:Anatomical education, Nursing students, Respiratory system, Lung, Swine
- Basic study on the effects of the use of BGM in auditory user interface on user’s memory and learning of directory hierarchy
- 論文掲載日：2016/12/31 第16巻
- Purpose: To provide cues to users for grasping the directory hierarchy in the operating environments of information technology devices when it is extremely difficult to use the sense of sight, we devised a user interface having a type of auditory landmark by playing simple music with no particular semantic structure as background music (BGM) for specific hierarchies. We performed a basic study of the effect of BGM on the users’ recall and learning of directory hierarchies and of the item names residing in them.
Subjects and method: The subjects were 12 healthy male university students between the ages of 21 and 22 (six for each of the experiment conditions). To avoid influencing the test results, we selected subjects who were not information science or music majors. We prepared a four-level tree-structured directory hierarchy, which was structured such that the first level had two branches, the second level had three branches, and the third level had three branches. There were 30 nodes and 80 items. We used information science terminology for the item names. The item names were read aloud using a screen reader. The arrow keys, enter key, and backspace key were used to move inside and between directories. We tested tasks of recall and learning of the directory hierarchy under two conditions: 1) with BGM (BGM was presented in three places in the hierarchy) and 2) without BGM. We performed six trials in total, two trials each day for three days.
Conclusion: Our findings are summarised as follows: (1) Memorising and learning by mapping the spatial arrangement of the directory with BGM enhanced the users’ spatial perception of the directory structure. (2) As a result, learning performance increased approximately 20% on an average. (3) This increased relatively the cognitive processing resources for applying the item names into memory, and learning efficiency increased by an average of approximately 30%.
Keywords: Auditory user interface, Non-visual user interface, Visual impairment, Human memories, Learning, Directory hierarchy
- Performance strategy in the hand mental rotation task in patients with schizophrenia
- 論文掲載日：2016/12/30 第16巻
- Purpose: We compared the response times for each presented angle in a hand mental rotation task (HMRT) in patients with schizophrenia in order to investigate performance strategies adopted when patients were required to determine whether a presented picture showed a left or right hand.
Patients and Methods: Twenty-three right-handed patients with schizophrenia (15 male and 8 female, mean age 39.5 ± 11.6 years) performed the HMRT. A total of 96 pictures randomly featuring left or right hands, either palm or back of hand, rotated in six different angles (at a 60° intervals) were presented to participants. Participants were instructed to determine the left or right for each picture as fast and as accurately as possible by pressing the left or right key.
Conclusion: Response times were longer for the angles that were difficult for participants to simulate. These results indicate that participants utilize a motor imagery strategy to perform HMRTs.
Keywords: Motor imagery, Mental disorder, Cognitive dysfunction, Reaction time, Motor response generation
- Performance strategy in the hand mental rotation task in hemiplegic stroke patients
- 論文掲載日：2016/11/02 第16巻
- Purpose: We compared the accuracy and response times for a hand mental rotation task (HMRT) in patients with hemiplegic stroke in order to investigate performance strategies adopted when patients were required to determine whether a presented picture showed a left or right hand.
Patients and Methods: Twenty-eight patients with hemiplegic stroke performed the HMRT (14 patients with left-hemisphere brain damage: 59.5 ± 15.8 years; 14 patients with right-hemisphere brain damage: 65.6 ± 14.9 years). Hand pictures featuring various combinations of three factors (left or right hand, palm or back of hand, and six angular orientations were randomly presented. The third finger pointing upward was defined as an angle of 0°, and clockwise rotation occurred in increments of 60°. Participants were instructed to use their non-paralyzed hand to press the button in the determined direction (e.g., in the case of a left hand picture, the left button was pressed) as quickly and as accurately as possible.
Results: The accuracy in the HMRT was lowest for angles of 180°, and an increasing trend in accuracy was observed as the picture was rotated clockwise or counterclockwise towards 0°. The ΔRT was also longest for angles of 180° and tended to decrease as 0° was approached. Moreover, when compared with RTs for pictures of hand angles that were easier to replicate, those for pictures of hand angles that were difficult to replicate were longer.
Conclusion: These results indicate that patients with hemiplegic stroke utilize a mental transformation strategy to perform HMRTs, and that this strategy involves simulation of one’s own hand movements (motor imagery strategy).
Keywords：Motor imagery, Hemiparesis, Reaction time, Response time, Motor response generation