2 edition of Subjective field study of response to impulsive helicopter noise found in the catalog.
Subjective field study of response to impulsive helicopter noise
Clemans A Powell
1981 by National Aeronautics and Space Administration, Scientific and Technical Information Branch, For sale by the National Technical Information Service] in Washington, D.C, [Springfield, Va .
Written in English
|Statement||Clemans A. Powell|
|Series||NASA technical paper -- 1833|
|Contributions||Langley Research Center, United States. National Aeronautics and Space Administration. Scientific and Technical Information Branch|
|The Physical Object|
|Pagination||40 p. :|
|Number of Pages||40|
The vibrations make the air move in waves, and these sound waves travel to the ear. When the sound waves enter the ear, the brain has to interpret them. The sound waves can also travel through other materials, such as water and even the solid earth. A gunshot is an example of an impulsive sound; the noise of a power lawnmower is a series of. Impulsive Responses. Type. immediate responses. Built into the mind is an instinctual base of reactions and attitudes that cannot be altered but merely compensated for. When a story's problem revolves around the unsuitability of someone's essential nature to a given situation or environment, the central issue concerns Impulsive Responses.
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One possibility for the inconclusiveness of subjective helicopter noise studies is the difficulty in adequately reproducing the complex waveforms or temporal patterns resulting from the low-frequency pulsative or impulsive character of helicopter noise.
As a consequence, a number of psychoacoustic. Subjects, located outdoors and indoors, judged the noisiness and other subjective noise characteristics of flyovers of two helicopters and a propeller driven airplane as part of Subjective field study of response to impulsive helicopter noise book study of the effects of impulsiveness on the subjective response to helicopter noise.
In the first experiment, the impulsive characteristics of one helicopter was controlled by varying the main rotor speed while maintaining a constant airspeed in level flight. Subjective field study of response to impulsive helicopter noise / By Clemans A.
Powell, United States. National Aeronautics and Space Administration. Scientific and Technical Information Branch.
and Langley Research Center. Abstract "April ""Langley Research Center."Includes bibliographical of access: Internet. The Subjective field study of response to impulsive helicopter noise book stimuli recorded during a recent field study consisted of 16 sounds, each presented at 4 peak noise levels.
Two helicopters and a fixed-wing aircraft were used. The impulsive characteristics of one helicopter were varied by operating at different rotor speeds, whereas the other helicopter, the noise of which was dominated by the tail rotor, displayed little variation in blade-slap by: 3. Subjective Field Study of Response to Impulsive Helicopter Noise, NASA Technical Paper() J.M.
Fields and C.A. Powell. Community reactions to helicopter noise: Results from an experimental study. The two major source mechanisms of helicopter impulsive noise are addressed: high-speed impulsive noise and blade- vortex interaction impulsive noise.
A thorough physical explanation of both generating mechanisms is presented together with model and full-scale measurements of the by: The present study investigates the role of helicopter noise-induced rattle (i.e.
sounds of rattling objects or windows within the dwelling induced by low frequency components impacting the building) in heightening the annoyance response. This was done by asking subjects to compare the annoyance due to recorded helicopter noise (either with or without rattle) with that due to fixed-wing aircraft noise File Size: KB.
A LABORATORY STUDY OF SUBJECTIVE ANNOYANCE RESPONSE TO SONIC BOOMS AND AIRCRAFT FLYOVERS By Jack D° Leatherwood and Brenda M. Sullivan Three experiments were conducted to determine subjective equivalence of aircraft subsonic flyover noise and sonic booms.
The knowledge about human perception of noise in outdoor recreational areas is limited. The aim of the present study was to study the relationship between different noise indicators and subjective responses to aircraft noise, aiming at developing applicable noise indicators in Cited by: Subjective responses to aircraft noise in an outdoor recreational setting: A combined field and Subjective field study of response to impulsive helicopter noise book study September Journal of Sound and Vibration ().
LEE, W. HARRIS and S. WIDNALL Journal o/Aircr A study of helicopter rotor rotational noise. SCHMITZ and D. BOXWELL Journal of the AmericanHelicopter Soci In-flight far field measurement of helicopter impulsive noise.
Cited by: 1. A laboratory study of the subjective response to helicopter blade-slap noise. By K. Shepherd. Abstract. The test stimuli recorded during a recent field study consisted of 16 sounds, each presented at 4 peak noise levels.
Two helicopters and a fixed-wing aircraft were used. The impulsive characteristics of one helicopter were varied by Author: K. Shepherd.
This assessment uses the Impulsive Noise Registry to assess the OSPAR Impulsive Noise Indicator, using data available from the first year of reporting (). Only partial data were provided by each of the contributing Contracting Parties (Belgium, Denmark, Germany, the Netherlands, Sweden and the UK), so the assessment cannot be considered.
Subjective field study of response to Subjective field study of response to impulsive helicopter noise book helicopter noise. Washington, D.C.: National Aeronautics and Space Administration, Scientific and Technical Information Branch ; [Springfield, Va.: For sale by the National Technical Information Service], (OCoLC) Material Type: Government publication, National government publication.
Helicopter noise exhibits distinctive acoustical characteristics (e.g., pulsation) compared to noise from propeller-driven aircraft which contains tonal components.
Whereas, at comparable sound exposure levels (L AE), annoyance reactions to these sources might be different, knowledge of potential annoyance differences is by: 5. Subjective field study of response to impulsive helicopter noise / (Washington, D.C.: National Aeronautics and Space Administration, Scientific and Technical Information Branch ; [Springfield, Va.: For sale by the National Technical Information Service], ).
In a NASÄ study on helicopter noise (Newman et al, ) the authors state that "DNL can be used with impulse adjustment of dB for the Sea King S61 and dB for the Bell Molino.
community response to helicopter noise is a sociological phenomenon rather than purely an acoustic problem. For example, one problem identified in the UK is that it is This paper summarizes the findings of this project with regard to subjective res-ponses to helicopter noise [Work funded by Defra, UK].
Field Study of Aircraft Noise and. Subjective field study of response to impulsive helicopter noise. NASA Technical Paper Robinson, D.
W., Whittle, L. S., and Bowsher, J. The Loudness of Diffuse Sound Fields, Acta Acustica united with Acustica, Vol Number 6, pp. â Rubin, D. Subjective Field Study of Response to Impulsive Helicopter Noise Clemans A. Powell: NASA: TP NASA Technical Reports Server (NTRS) Evaluation of the Annoyance Due to Helicopter Rotor Noise Harry Sternfeld, Jr., Linda Bukowski Doyle: NASA: CR NASA Technical Reports Server (NTRS).
Powell conducted two controlled-listening studies in which 91 test participants located both indoors and outdoors judged the noisiness of 72 helicopter and propeller-driven, fixed-wing Powell, C.A.
() Subjective Field Study of Response To Impulsive Helicopter Noise, NASA Technical Paper Should Helicopter Noise Be Measured Differently From Other Aircraft John A. Molino: NASA: CR NASA Technical Reports Server (NTRS) Subjective Field Study of Response to Impulsive Helicopter Noise Clemans A.
Powell: NASA: TP NASA Technical Reports Server (NTRS) The Improvement of Helicopter Noise Management in the UK.
In-ear dosimetry and noise exposure feedback were used to modify worker attitude and behavior regarding hearing protection use.
The study specifically addressed whether providing in-ear noise exposure data to workers resulted in a reduction in average noise dose rate equivalent continuous levels. Nineteen combat arms instructors (impulse noise group) and heavy equipment operators (continuous Author: Jesse Trawick, Jeremy Slagley, Robert Eninger.
the presented study is to develop a measure of impulsiveness which quantifies the perception of impulsive content within a sound in an accurate, yet simple, manner. The methodology used to first develop the impulsiveness measure and then the perceived annoyance measure for impulsive sounds is described herein, and is an extension of a previousFile Size: KB.
texts All Books All Texts latest This Just In Smithsonian Libraries FEDLINK (US) Genealogy Lincoln Collection. Books to Borrow. Top Full text of "Should helicopter noise be measured differently from other aircraft noise A review of the psychoacoustic literature".
deconvolved impulse response. • The excitation signal and the deconvolution technique must enable the elimination of non linear artifacts in the deconvolved impulse response.
In general, the signal-to-noise ratio is improved by taking multiple averagesof the measured output signal before the impulse response deconvolution process is by: Abstract In-plane impulsive noise, radiating from a hovering model rotor has been measured in an anechoic environment.
The hover acoustic signature was compared with existing theoretical prediction models and with previous forward flight experiments using the same model rotor.
Show Slide FSTCC Impact/Impulse Noise. Impact, or impulse noise. The first type of n oise is one that we are exposed to quite often during normal training and in combat. Impulse or impact noise is very loud and comes in short bursts.
It is characterized by a sharp rise in intensity followed by a rapid decline in Size: 45KB. A library of important research documents on rotorcraft noise. Welcome to the AHS International library of important research documents on rotorcraft er available, links to publicly accessible documents are provided.
No effect was detected in the impulse noise population, likely due to limitations of dosimeter technology in response to impulse noise. No correlation between worker attitudes towards hearing protection and noise dose rate equivalent continuous level was detected for either group (continuous p = ; impulse p = ).
In this study the effects on hearing induced by occupational exposure to impulse noise were compared with those induced by exposure to continuous steady state noise.
Three groups exposed to impulse noise, one group exposed to continuous steady state noise, and an Cited by: Start studying chpt18ptec Learn vocabulary, terms, and more with flashcards, games, and other study tools.
Shepherd, Kevin P. Subjective Evaluation of Noise from Light Aircraft. University of Utah, NASA CR (Dec. Shepherd, Kevin P. Laboratory Study of the Subjective Response to Helicopter Blade-Slap Noise.
The Bionetics Corp., NASA CRContract NAS (Dec. A subject for further research is the elucidation of the mechanisms underlying noise-induced cardiovascular disorders and the relationship of noise with annoyance and nonacoustical factors modifying health outcomes.
A high priority study subject is the effects of noise on children, including cognitive effects and their by: ABSTRACT This study was undertaken to evaluate subjective and objective aspects of moderate levels of noise from impulsive sources. The study excluded evaluation of hearing damage risk or annoyance from building vibration by high level impulsive noise, which were covered by recent recommendations of the National Research Council, Committee on Hearing Bioacoustics and.
Multiple studies demonstrate powerful protection of hair cells and cochlear blood flow in animals treated with NAC alone, resulting in reduced permanent hearing loss, both prior to and following impulse noise. (48), (49), (50) Human studies using 1, mg of NAC daily for two weeks in military recruits exposed to impulse noise at peak levels as high as dB, and in civilian workers exposed.
A Study of Impulse Response System Identification Degree Project of 10 credit points evaluate the complete capability of the approach to the noise vari ation a study of signal to the challenges for the field are in modeling and developing ofmore complex. time domain properties of the asynchronous impulsive noise, such as impulse inter-arrival times, impulse durations, and in-stantaneous statistics, have been experimentally investigated in , , , .
We refer the reader to  and  for modeling the impulse inter-arrival times and impulse durations.Subjective Field Study of Response to Impulsive Helicopter Noise, NASA Technical PaperApril 72 P.D.
Schomer and L.R. Wagner,On the Contribution of Noticeability of Environmental Sounds to Noise Annoyance, Noise Control Eng.
J., 44(6),Nov-Dec 73 EPA,Information on Levels of. An example is white noise, which on average has a flat frequency spectrum. Through a mathematical operation on the response signal and the white noise excitation signal (deconvolution), the impulse response can be extracted.
Due to the randomness of the excitation signal, the extracted impulse response shows residual noise, which is reduced as the. CHARACTERIZATION OF IMPULSE NOISE AND HAZARD ANALYSIS OF IMPULSE NOISE INDUCED HEARING Pdf USING AHAAH MODELING Pdf Qing Wu A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of Master in the field of Electrical & Computer Engineering Approved by: Dr.
Qin Jun, Chair Dr. Lalit Gupta Dr. Haibo Wang Graduate School.where * denotes convolution and Download pdf is the duration of the measured cavity impulse the time-delay information reversed, h(T - t) propagates inside the cavity following the same multipath ray trajectories, consequently removing the multipath delays and allowing the waves to focus at the output port to from a compressed short pulse at t = T.The study has been conducted by the CAA in ebook with research teams from the Universities of Ebook, Manchester, and Southampton.
The objectives of the study were to determine: (a) the relationships between outdoor aircraft noise levels and the probability of sleep disturbance; and (b) the variation of these relationships with time.