507results about How to "Reduce wind noise" patented technology

The invention includes a method, apparatus, and computer program to selectively suppress wind noise while preserving narrow-band signals in acoustic data. Sound from one or several microphones is digitized into binary data. A time-frequency transform is applied to the data to produce a series of spectra. The spectra are analyzed to detect the presence of wind noise and narrow band signals. Wind noise is selectively suppressed while preserving the narrow band signals. The narrow band signal is interpolated through the times and frequencies when it is masked by the wind noise. A time series is then synthesized from the signal spectral estimate that can be listened to. This invention overcomes prior art limitations that require more than one microphone and an independent measurement of wind speed. Its application results in good-quality speech from data severely degraded by wind noise.

An acoustic data collection system that uses an antenna array aboard a powered unmanned and remotely controlled parafoil. The antenna array has multiple microphone elements, whose outputs are combined to provide directionality to the data acquisition.

By monitoring the wind noise in a location in which a cellular telephone is operating and by applying noise reduction and/or cancellation protocols at the appropriate time via analog and/or digital signal processing, it is possible to significantly reduce wind noise entering into a communication system.

A noise reducing apparatus is disclosed, which includes: input means for inputting multiple audio signals from multiple audio channels; multiple band extracting means for extracting a predetermined band from the multiple audio signals; calculating means for averaging signals from the multiple band extracting means; multiple first level detecting means for detecting the signal levels in a predetermined period of time of the signals from the multiple band extracting means; second level detecting means for detecting the signal level in a predetermined period of time of the signal from the calculating means; selecting means for selecting, for each of the predetermined period of times, the signal having the lowest level value of the level values detected by the multiple first level detecting means and the second level detecting means; band limiting means for limiting the band of the signal from the selecting means; and band synthesizing means for band-synthesizing the signal from the band limiting means and the signal in a band, which is not extracted by the multiple band extracting means, for each audio channel, wherein the output of the band synthesizing means is an audio channel output signal.

A side wall of a centrifugal fan includes a gap expanding portion arranged to gradually expand a gap between an impeller and the side wall from an upstream end toward a downstream end with respect to a rotation direction of a rotating portion. In the centrifugal fan, an electronic component arranging portion of a board is arranged in an area surrounded by the gap expanding portion, the impeller, and an air outlet, and accordingly does not overlap with a motor or the impeller in an axial direction. The electronic component arranging portion is arranged in an area extending, in a circumferential direction about a central axis, from a position 180 degrees upstream from a middle of the air outlet downstream to the middle of the air outlet, that is, in an area where a wind channel has a large width.

An elevator installation includes an elevator car that moves in an elevator shaft with shaft doors and which car has at least one car apron arranged parallel to a plane of a shaft wall at a shaft door side. A device for reducing noises generated by the air flow arising between the shaft wall and the car apron includes sound-absorbing material that is mounted at the car apron and at the shaft wall.

In a portable cutting tool configured to perform a cutting operation through movement along the upper surface of a workpiece, when an ordinary inner rotor type motor is used as the drive source, the motor is rotated at high speed to obtain a high output, which is reduced in speed by a speed reduction device to thereby secure an appropriate rotational speed for a rotary cutter. Since the electric motor is rotated at high speed in this construction, there have been problems of noise, vibration, etc. The present invention aims to achieve a reduction in the noise and vibration of the cutting tool.

A direct drive system is incorporated with an outer rotor type electric motor (11) used as the drive source and with a rotary cutter (12) directly mounted to an output shaft (11d) of the motor, and the electric motor (11) is rotated at an appropriate rotational speed for the rotary cutter (12), for example, at approximately 6,000 RPM, whereby it is possible to achieve a reduction in the noise and vibration of the cutting tool 1.

A cooling module is presented, which includes a heat sink and a fan unit. The heat sink provides a base plate and a plurality of fins, with an outlet extending through the base plate and the fins formed on a first surface of the base plate, and with a second surface of the base plate attached to a heat generating unit. The fan unit is rotatably mounted on the heat sink and aligned with the outlet. With the above-mentioned structure, an air-guiding channel is formed between any adjacent two of the fins and communicates with the outlet for a part of air outputted by the fan unit to be guided through the air guiding channels and exhausted by the outlet. Consequently, disturbed flows and wind noise are decreased while cooling efficiency is improved.

A system and method for reducing the operational noise of a blunt trailing edge of a wind turbine blade is described. The system involves increasing the trailing edge solid angle at the blade trailing edge by providing a wedge element or projection adjacent the trailing edge of the blade, the wedge element acting to provide improved mixing of the suction side and pressure side flows at the blunt trailing edge, thereby reducing the strength of vortex shedding at the trailing edge and the associated operational noise.

A centrifugal multi-blade fan has multiple blades about a rotational shaft and draws in air along the rotational shaft and then blows the air approximately perpendicular to the rotational shaft to reduce wind noise. A scroll casing encloses the multi-blade fan and defines a scroll-shaped airflow passage for directing the air blown from the multi-blade fan. The scroll casing has an intake opening and an outlet opening at a scroll end, in a downstream scroll casing portion. The scroll casing expands such that a flow passage cross-sectional area on the airflow downstream side is larger than that on an airflow upstream side. A ratio of a blade length to a diameter of the multi-blade fan is greater than or equal to 0.12, and an outer scroll casing radius, relative to the rotational axis, increases as a logarithmic spiral, its expansion angle being from 3.3° to 4.8°.

The invention discloses an automatic adjustable automobile wind tunnel testing platform with the function of interference elimination. The testing platform comprises a testing bench, an automatic wheel base adjusting part, and a tread adjusting part. The testing bench is installed on a wind tunnel testing segment floor and covers a balance support. The automatic wheel base adjusting part is installed at the lower part of the balance support; and the tread adjusting part is installed in the balance support. The automatic wheel base adjusting part consists of a wheel base displacement sensor, a gear rack driving device, a drive motor, a wheel base adjustment support and a guide rod; the wheel base adjustment support is fixed at the bottom of the balance support; the guide rod passes through the wheel base adjustment support and the is connected with a balance floating frame; the wheel base adjustment support can move axially along the guide rod; the wheel base displacement sensor is arranged on the wheel base adjustment support; and the wheel base adjustment support is connected with the drive motor by the gear rack driving device. According to the invention, the interference on the process quality by the support exposed in the flow field in wind tunnel testing can be eliminated; and supports of vehicles with different wheel bases and threads can be realized.