scholarly journals Discussion of the Relation between Initial Time Delay Gap (ITDG) and Acoustical Intimacy: Leo Beranek’s Final Thoughts on the Subject, Documented

Acoustics ◽  
2019 ◽  
Vol 1 (3) ◽  
pp. 561-569 ◽  
Author(s):  
Jerald R. Hyde
Keyword(s):  
Time Delay ◽  
Visual Input ◽  
Initial Time ◽  
Acoustical Parameters ◽  
Delay Times ◽  
Concert Halls ◽  
Objective Factor ◽  
The Subject ◽  
Music Acoustics ◽  
Important Objective

Current discussions on the objective attributes contributing to concert hall quality started formally in 1962 with the publication of Leo Beranek’s book “Music, Acoustics, and Architecture”. From his consulting work in the late 1950s, Beranek determined that in narrow halls, the short early delay times were an important factor in quality. Needing a measurable acoustical factor, rather than a dimensional one, he chose to define the initial time delay gap (ITDG) for a specific location near the middle of the hall’s main floor. Many acousticians failed to understand the simplicity of this proposal. Beranek had learned that long first delays sounded “arena-like” and “remote”, and, thus, not “intimate”. This bolstered his belief that ITDG was an important objective factor he decided to call “intimacy”. Most acoustical parameters can be directly measured and sensed by the listener, such as reverberation decay, sound strength, clarity. “Intimacy” however is a feeling, and over the past two decades, it has become apparent that it is a multisensory attribute influenced by visual input and perhaps other factors. [J.R. Hyde, Proc. IOA, London, July 2002, Volume 24, Pt. 4, “Acoustical Intimacy in Concert Halls: Does Visual Input affect the Aural Experience”?] Beranek’s paper “Comments on “intimacy” and ITDG concepts in musical performing spaces”, [JASA 115, 2403 (2004)] finally acknowledged the multisensory aspects of “intimacy” and stated this choice of the word “may have been unfortunate”. He further separated the term “intimacy” from ITDG. Documentation of this pronouncement will be provided in the paper.

Perceived self-motion in two visual contexts: Dissociable mechanisms underlie perception

2006 ◽  
Vol 16 (1-2) ◽  
pp. 23-28 ◽  
Author(s):  
W. Geoffrey Wright ◽  
Paul DiZio ◽  
James R. Lackner
Keyword(s):  
Motion Perception ◽  
Path Integration ◽  
Visual Input ◽  
Visual Scene ◽  
Spatial Context ◽  
Immersive Virtual Environment ◽  
Physical Context ◽  
The Subject ◽  
Self Motion ◽  
Visual Acceleration

We evaluated the influence of moving visual scenes and knowledge of spatial and physical context on visually induced self-motion perception in an immersive virtual environment. A sinusoidal, vertically oscillating visual stimulus induced perceptions of self-motion that matched changes in visual acceleration. Subjects reported peaks of perceived self-motion in synchrony with peaks of visual acceleration and opposite in direction to visual scene motion. Spatial context was manipulated by testing subjects in the environment that matched the room in the visual scene or by testing them in a separate chamber. Physical context was manipulated by testing the subject while seated in a stable, earth-fixed desk chair or in an apparatus capable of large linear motions, however, in both conditions no actual motion occurred. The compellingness of perceived self-motion was increased significantly when the spatial context matched the visual input and actual body displacement was possible, however, the latency and amplitude of perceived self-motion were unaffected by the spatial or physical context. We propose that two dissociable processes are involved in self-motion perception: one process, primarily driven by visual input, affects vection latency and path integration, the other process, receiving cognitive input, drives the compellingness of perceived self-motion.

Variability of Positioning Accuracy following a Maximum Isometric Contraction

1987 ◽  
Vol 64 (3) ◽  
pp. 759-764 ◽  
Author(s):  
Bruce R. Etnyre ◽  
Eva J. Lee ◽  
Hally B. W. Poindexter
Keyword(s):  
Isometric Contraction ◽  
Constant Error ◽  
Elbow Extension ◽  
Positioning Accuracy ◽  
Extensor Muscles ◽  
Delay Times ◽  
Contraction Times ◽  
The Subject ◽  
Experimental Trials ◽  
Elbow Extensor

The purpose of this study was to examine the effects of different contraction times and delay times prior to a positioning task. While blindfolded, each of 25 subjects learned to produce elbow-extension movements to a short and a long target using a kinesthesiometer. The subject then produced 30 trials without feedback to each target. These control trials were preceded by a foreperiod of 0-, 3-, or 6-sec. delay. The 60 experimental trials were identical to control trials except the subject isometrically contracted elbow extensor muscles for 3 or 6 sec. prior to each trial. Following each isometric contraction the subject delayed movement for 0, 3, or 6 sec. The 3-sec. and 6-sec. prepositioning contractions produced greater undershooting and variability than no prepositioning contractions, and the 0-sec. delay produced less constant error than either the 3- or 6-sec. delay. It was concluded that following isometric contraction, undershooting a target occurred and this effect did not dissipate within a 6-sec. period.

scholarly journals Developments in Concert Hall Acoustics in the 1960s: Theory and Practice

Acoustics ◽  
2019 ◽  
Vol 1 (3) ◽  
pp. 538-548 ◽  
Author(s):  
Mike Barron
Keyword(s):  
New York ◽  
Subjective Effects ◽  
Theory And Practice ◽  
Initial Time ◽  
Directional Sensitivity ◽  
Energy Fraction ◽  
Concert Hall ◽  
Anechoic Chambers ◽  
Concert Halls ◽  
The 1960S

After the war, there was a general understanding of reverberation time (RT), including how to measure it and its significance, as well as its link to a state of diffusion. Reverberation refers to a property of late sound; there was an appreciation that early sound must be significant, but in what way? Research had begun in the 1950s using simulation systems in anechoic chambers, with the Haas effect of 1951 being the most prominent result. Thiele’s Deutlichkeit, or early energy fraction, was important from 1953 and indirectly found expression in Beranek’s initial time delay gap (ITDG) from 1962. The 1960s produced a possible explanation for RTs in halls being shorter than calculations predicted, the importance of early sound for the sense of reverberation (EDT), the nature of directional sensitivity, conditions for echo disturbance, and the importance of early lateral reflections. Much of the research in the 1960s laid the foundations for research investigating the relative importance of the various subjective effects for concert hall listening. Important concert halls built during the period include Philharmonic Hall, New York (1962); Fairfield Hall, Croydon, London (1962); the Philharmonie, Berlin (1963); and De Doelen Hall, Rotterdam (1966). The parallel-sided halls of the past were rarely copied, however, due to architectural fashion. These various halls will be discussed as they make a fascinating group.

Detecting Changes in One's Own Velocity from the Optic Flow

Perception ◽  
1994 ◽  
Vol 23 (6) ◽  
pp. 681-690 ◽  
Author(s):  
Jos Monen ◽  
Eli Brenner
Keyword(s):  
Optic Flow ◽  
Flat Surface ◽  
Visual Input ◽  
Stereoscopic Depth ◽  
Forward Motion ◽  
The Subject ◽  
Better Than

Experiments were designed to establish whether we can use the optic flow to detect changes in our own velocity. Subjects were presented with simulations of forward motion across a flat surface. They were asked to respond as quickly as possible to a step increase in simulated ego-velocity. The smallest change for which subjects could respond within 500 ms was determined. At realistic simulated speeds of locomotion, the simulated ego-velocity had to increase by about 50%. The threshold for detecting changes in simulated ego-velocity was hardly better than the threshold for detecting other changes in the acceleration of the dots on the screen. It made little difference whether the surface across which the subject appeared to move was built up of dots, lines, or triangles; neither did it matter whether subjects saw the same image with both eyes, or whether the simulation was presented in stereoscopic depth. The results show that we are very poor at detecting changes in our own velocity on the basis of visual input alone.

scholarly journals هێرمنيۆتيزه‌كردنى بوونگه‌راييانه‌ى مێژوو له ‌ڕۆمانى (كه‌شتيى فريشته‌كان)ى به‌ختيار عه‌لى- دا

2019 ◽  
Vol 6 (2) ◽  
pp. 414-441
Author(s):  
ئیبراهیم عبدالرحمن محمود & ئارى عوسمان ڕۆستهم
Keyword(s):  
Human Existence ◽  
Historical Event ◽  
The Novel ◽  
The Third ◽  
The Subject ◽  
Arabic And English ◽  
Concept Of Beauty ◽  
Important Objective

Abstract: This research, which is entitled "Existentialism Interpretation of the history in the story of Angel Ship's by (Bakhtiar Ali)) represents an effort to the study of the historical event through the context of the novel in terms of Existentialism philosophy and based on the Existentialism method of intrtpretation because the novel (Angel`s Ship) is considered as the biggest novel attempt by it`s author so far. The research consists of two sectons and the most important objective that the researcher has reached. The first section consists of two axes. The first one deals with the terminology of history and the ways to define it according ti the scientific criteria while the second one deals with the most important philosophical doctrines and their perspectives with defining it`s terminology. The second section of the research consists of four axes. The first one deal with clarifying the author`s perspective and how to comprehend and present history. The second one is about the historical human existence and the ways to reach this existence. The third one deals with the subject of controlling the history and the human status in this field. The fourth one consists of the concept of beauty nd how to lead it to the safety, followed by the results that have been reached with the list of the different references and abstract in both languages: Arabic and English.

An Alternative Approach to Time Delay Prior to Inspection for Hydrogen Cracking

2018 ◽  
Author(s):  
William A. Bruce ◽  
Jared Proegler ◽  
Brad Etheridge ◽  
Steve Rapp ◽  
Russell Scoles
Keyword(s):  
Time Delay ◽  
Delay Time ◽  
Good Practice ◽  
Welding Process ◽  
Time Dependent ◽  
Hydrogen Cracking ◽  
Slow Cooling ◽  
Alternative Approach ◽  
Delay Times ◽  
Hydrogen Assisted Cracking

Hydrogen-assisted cracking in welds, which is also referred to as ‘hydrogen cracking’ or ‘delayed cracking,’ often requires time to occur. The reason for this is that time is required for the hydrogen to diffuse to areas with crack susceptible microstructures. Prior to inspection for hydrogen cracking, general good practice indicates that a sufficient delay time should be allowed to elapse — to allow any cracks that are going to form to do so and for the cracks to grow to a detectable size. What is a ‘sufficient’ delay time? Why does a delay time tend to be required for some applications (e.g., installation of a hot tap branch connection) and not for others (e.g., construction of an offshore pipeline from a lay barge)? This paper will address these and other related questions and present the results of recent experimental work on this subject. When determining appropriate delay times prior to inspection, it is important to consider not only the time-dependent nature of hydrogen cracking, but also the expected susceptibility of the weld to cracking. From a time-dependent nature standpoint, longer delay times decrease the chance that cracking can occur after inspection has been completed. From a probability standpoint, if measures can be taken to assure that the probability of cracking is extremely low, then determining an appropriate delay time becomes a moot point. In other words, if the weld is never going to crack, it does not matter when you inspect it. The probability of cracking can be minimized by using more conservative welding procedures (i.e., by designing out the risk of hydrogen cracking during procedure qualification). For example, if hydrogen levels are closely controlled by using low-hydrogen electrodes or a low-hydrogen welding process, or if the hydrogen in a weld made using cellulosic-coated electrodes is allowed to diffuse away after welding by careful application of preheating and slow cooling, or the use of post-weld preheat maintenance (i.e., post-heating), the probability of cracking is significantly reduced, and immediate inspection may be justified. This alternative approach to time delay prior to inspection for hydrogen cracking, which can allow for immediate inspection, will be presented.

Evaluation of Audio Response Time Delay Requirements for Digitized Audio

1989 ◽  
Vol 33 (4) ◽  
pp. 234-238 ◽  
Author(s):  
Paula M. Van Balen ◽  
Leslie R. Eisler
Keyword(s):  
Time Delay ◽  
Response Time ◽  
Time Delays ◽  
Response Times ◽  
System Response ◽  
System Response Time ◽  
The Subject ◽  
Different Response ◽  
Voice Data ◽  
Subject Performance

As digital voice data is increasingly replacing analog in system applications, user interface requirements supporting this technology must be established. This experiment was conducted to determine whether system response time affected a user's ability to control movement of recorded speech while keying in a verbatim report of the speech content. Experienced subjects performed a transcription task under four different response times. Upon completion of the task, the subject ordered the response times from shortest to longest and rank-ordered their preferences for response delay times. Performance data was collected to discover if response time differences affected performance. Subjects were unable to identify the response time delays correctly; and, based on the preference rankings, the subjects were most satisfied with a response time delay range between 100 ms and 150 ms and least satisfied with a response time delay of 250 ms. Subjects stated that with the longest and shortest response time delays they had trouble positioning in the audio. Response time delays did not affect subject performance, although other significant results were found.

Sign in / Sign up

Export Citation Format

Share Document