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A 1973 report cites a university study of fifty cases of people complaining about a "low throbbing background noise" that others were unable to hear. The sound, always peaking between 30 and 40 Hz (hertz), was found to only be heard during cool weather with a light breeze, and often early in the morning. These noises were often confined to a 10 ...
As a result of increased sales of full electric vehicle and hybrid electric vehicles in several countries, some members of the blind community have raised concerns about the noise reduction when those vehicles operate in all-electric mode, as blind people or the visually impaired consider the noise of combustion engines a helpful aid while crossing streets and think quiet hybrids could pose an ...
Noise, vibration, and harshness (NVH), also known as noise and vibration (N&V), is the study and modification of the noise and vibration characteristics of vehicles, particularly cars and trucks. While noise and vibration can be readily measured, harshness is a subjective quality, and is measured either via jury evaluations, or with analytical ...
Roadway noise is the collective sound energy emanating from motor vehicles. It consists chiefly of road surface, tire, engine/transmission, aerodynamic, and braking elements. Noise of rolling tires driving on pavement is found to be the biggest contributor of highway noise and increases with higher vehicle speeds. [1] [2] [3]
The torsional deflection of a simple cylinder cannot radiate efficiently acoustic noise, but with particular boundary conditions the stator can radiate acoustic noise under torque ripple excitation. [8] Structure-borne noise can also be generated by torque ripple when rotor shaft line vibrations propagate to the frame [9] and shaft line.
"There's a strange noise coming through the speaker," Williams said "I don't know what's making it," he later added. The conversation was uploaded by a NASA Space Flight forum member on Saturday ...
This reduces noise in problem areas although trains make a distinctive tonal sound on freshly-ground track due to the pattern on the rail left by the grinding process, which wears flat over time. Rail squeal is a sound caused by a train's wheels slipping under specific conditions, usually around sharp curves.
Diagram showing how a car horn works. A horn grille is a part of some designs of car or other motor vehicle that has an electric horn, such as a motor scooter. Larger, louder air horns, as found on trucks (lorries) and buses, are driven by air compressors, or supplied by reservoirs charged to operate their air brakes. The compressor forces air ...