Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 78
Book Description
A Study of Noise Metric and Tone Correction Accuracy
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 78
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 78
Book Description
NASA Reference Publication
Author:
Publisher:
ISBN:
Category : Astronautics
Languages : en
Pages : 460
Book Description
Publisher:
ISBN:
Category : Astronautics
Languages : en
Pages : 460
Book Description
NASA Technical Paper
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 78
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 78
Book Description
NASA Technical Memorandum
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 52
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 52
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 304
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 304
Book Description
NASA Technical Paper
Author: United States. National Aeronautics and Space Administration
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 52
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 52
Book Description
Correction Procedures for Aircraft Noise Data. Volume IV. Tone Perception
Author: D. N. May
Publisher:
ISBN:
Category :
Languages : en
Pages : 75
Book Description
The existing tone correction procedure in the Effective Perceived Noise Level (EPNL) calculation procedure required for aircraft certification under Part 36 of the Federal Aviation Regulations was compared with other tone correction procedures, including the SAE Aerospace Recommended Practice 1071 and a multitone procedure due to Kryter and Pearsons. Different amounts of tone correction (level-weightings) and varying degrees of tone correction at different times in the flyover (time-weightings) were also explored. Also studied was a measure of spectral fluctuation, developed by NASA and known as spectral change. The research was limited to considering revisions within the framework of one-third octave, 0.5 second interval analysis, since such revisions can be quite easily implemented. The various tone correction noise metrics were tested against subjective judgements furnished by NASA of the noise from a range of propjet, turbojet, low and high bypass ratio turbofan, and supersonic commercial aircraft. It was found that a revision based on spectral change could, after further development, be a means to improve the accuracy of the EPNL metric. However, the success of the various other potential revisions depended on the characteristics of the data base tested. It was shown that research into improved metrics should be based on experimental plans which account for the correlations among the noise variables and the presence of any interactions. A separate, psychoacoustical pilot experiment was also performed into the effects of pseudotones on judged noisiness. (Pseudotones are low frequency tones introduced into a measured spectrum by ground reflections near the microphone).
Publisher:
ISBN:
Category :
Languages : en
Pages : 75
Book Description
The existing tone correction procedure in the Effective Perceived Noise Level (EPNL) calculation procedure required for aircraft certification under Part 36 of the Federal Aviation Regulations was compared with other tone correction procedures, including the SAE Aerospace Recommended Practice 1071 and a multitone procedure due to Kryter and Pearsons. Different amounts of tone correction (level-weightings) and varying degrees of tone correction at different times in the flyover (time-weightings) were also explored. Also studied was a measure of spectral fluctuation, developed by NASA and known as spectral change. The research was limited to considering revisions within the framework of one-third octave, 0.5 second interval analysis, since such revisions can be quite easily implemented. The various tone correction noise metrics were tested against subjective judgements furnished by NASA of the noise from a range of propjet, turbojet, low and high bypass ratio turbofan, and supersonic commercial aircraft. It was found that a revision based on spectral change could, after further development, be a means to improve the accuracy of the EPNL metric. However, the success of the various other potential revisions depended on the characteristics of the data base tested. It was shown that research into improved metrics should be based on experimental plans which account for the correlations among the noise variables and the presence of any interactions. A separate, psychoacoustical pilot experiment was also performed into the effects of pseudotones on judged noisiness. (Pseudotones are low frequency tones introduced into a measured spectrum by ground reflections near the microphone).
Sonic-boom Research
Author: Harvey H. Hubbard
Publisher:
ISBN:
Category : Sonic boom
Languages : en
Pages : 52
Book Description
Publisher:
ISBN:
Category : Sonic boom
Languages : en
Pages : 52
Book Description
Aeroacoustics of Flight Vehicles: Noise control
Author: Harvey H. Hubbard
Publisher:
ISBN:
Category : Aerodynamic noise
Languages : en
Pages : 452
Book Description
Publisher:
ISBN:
Category : Aerodynamic noise
Languages : en
Pages : 452
Book Description
Aeroacoustics of Flight Vehicles
Author: Harvey H. Hubbard
Publisher:
ISBN:
Category : Aerodynamic noise
Languages : en
Pages : 456
Book Description
Publisher:
ISBN:
Category : Aerodynamic noise
Languages : en
Pages : 456
Book Description