摘要:
A noise reduction processing apparatus includes a timing signal detection unit that detects an operation timing signal indicating a timing when an operation unit is operated, an audio signal acquisition unit that acquires an audio signal, and on the basis of the operation timing signal, a noise reduction processing unit that calculates first frequency spectra of an audio signal acquired during a time period which has high possibility that noise caused by an operation of the operation unit is generated and second frequency spectra of an audio signal acquired during a time period which has high possibility that the noise is not generated, and calculates a noise reduction audio signal obtained by performing noise reduction to the audio signal on the basis of frequency spectra in which at least a part of the calculated first frequency spectra are replaced with corresponding portions of the calculated second frequency spectra.
摘要:
One or more parts of an optical fiber is(are) exposed to a high temperature of gas flame for about 30 minutes so as to form one or more radially expanded core part(s) where a diameter of a core of the optical fiber is increased greater than its original size at a center and moderately decreased back to its original size as departing from the center. A part of the transmitting light leaks to the clad at the radially expanded core part. Leaked light hardly travels through the clad from the radially expanded core part to the output end of the optical fiber. This provides a function of an optical attenuator. Also, the attenuation is precisely adjusted to a desired level by controlling a size of the radially expanded core part. Furthermore, as an incident angle of the transmitting light from the core to the clad at the radially expanded core part becomes greater than conventional one, reflecting back the transmitting light to input side is prevented and the reflectance is minimized.