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Showing 1 to 10 of 10 for “"Active Noise Reduction"”.
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An Investigation of Performance Limitations in Active Noise Reduction Headsets
Closed-loop performance of an active noise reduction (ANR) headset is limited by phase lag. Speaker dynamics, control hardware, and acoustic wave propagation from the control speaker to the error microphone all contribute to this phase lag. Understanding these sources of phase lag and their …
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Concurrent substrate coupling noise modeling and active noise reduction methodology for mixed-signal physical design
… contamination caused by substrate coupling noise is a critical issue. Fast digital transients can produce noise harmful to the sensitive analog circuits. The noise can be coupled from noisy devices and interconnects into the common substrate and coupled into analog devices. This noise …
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The Detection of Warning Signals While Wearing Active Noise Reduction and Passive Hearing Protection Devices
… thresholds changed when individuals wore an active noise reduction (ANR) hearing protection device (HPD), a passive HPD, or no HPD. An ANR earmuff, a passive earmuff, and a user-molded foam earplug were tested in two types of noises (pink and red) at two different noise levels (85 dBA and 100 …
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Active noise reduction headphone measurement: Comparison of physical and psychophysical protocols and effects of microphone placement
Currently in the United States, Active Noise Reduction (ANR) headphones cannot be tested and labeled as hearing protection devices (HPDs) due to inherent limitations with the existing psychophysical headphone testing standard, real-ear attenuation at threshold (REAT). This research focused on the …
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Speech intelligibility in tracked vehicles and pink noise under active noise reduction and passive attenuation communications headsets
… three headset systems, two passive and one with active noise reduction technology, were conducted. Nine listeners, six males and three females, responded to 180 50-word Modified Rhyme Word Lists presented under two noise conditions, two conditions of bilateral phase reversal of the speech signal, …
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Active Noise Reduction Versus Passive Designs in Communication Headsets: Speech Intelligibility and Pilot Performance Effects in an Instrument Flight Simulation
… another potentially more ominous result of this noise-intense environment is the masking of the radio communications. Radio communications must remain intelligible, as they are imperative to the safe and efficient functioning of the airspace, especially the airspace surrounding our busiest …
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On Implemintation of Loudspeakers for Feedback Control, Open-Air, Active Noise Control Headsets
The loudspeakers used in active noise reduction (ANR) headsets are generally identical to loudspeakers used in commercial headphones. Unfortunately, the frequency response characteristics of these loudspeakers are not particularly well suited for open-air active noise control (ANC). Open-air …
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The Effects of Noise on Speech Intelligibility and Complex Cognitive Performance
… experiment was conducted to assess whether a reduction in noise at the ear would cause an improvement in speech intelligibility, an improvement in cognitive performance, and/or a reduction in subjective mental workload. Modified Rhyme Test (MRT) stimuli were used to determine intelligibility …
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An Examination of Headset, Hearing Sensitivity, Flight Workload, and Communication Signal Quality on Black Hawk Helicopter Simulator Pilot Performance
… Army rotary-wing aviators are exposed is intense noise generated from the aircraft. The potential for permanent hearing loss and difficulty communicating in helicopter noise is well known; an appropriate way to evaluate a hearing-impaired pilot's safety risk due to hearing loss is not as well …
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Adjoint-based control of turbulent jet noise
Noise is an important factor in certifying an airplane and more restrictive noise regulations have demanded the design of quieter aircraft, with much of the emphasis focused on lower jet-noise emission. Previous passive and active noise-reduction strategies required parametric experiments or …