Abstract: A noise reduction device is used together with a shell which surrounds at least a part of the periphery of reclinable seat. The device includes a plurality of noise microphones, a noise controller, and control speakers. Control speakers output a sound based on a control-sound signal that is generated by the noise controller. Each of noise microphones is accommodated in back wall configuring the shell and is set back from a surface of the back wall.

Abstract: A noise reduction device is used together with a shell which surrounds at least a part of the periphery of reclinable seat. The device includes a plurality of noise microphones, a noise controller, and control speakers. Control speakers output a sound based on a control-sound signal that is generated by the noise controller. Each of noise microphones is accommodated in back wall configuring the shell and is set back from a surface of the back wall.

Abstract: In a case where a desired radio frequency channel is searched over a plurality of radio frequency channels through manual switching, a received data error detection section 12 detects an error rate of radio data, and an electric field detection section 11 detects a field strength. System information comparison section 6 detects a match or mismatch between the system information of the radio frequency channel and the system information of a wireless selective paging receiver. A display section 3 indicates the result of such detection in the form of an at-a-glance list in decreasing order of receiving probability, thereby enabling the user to select a radio frequency channel having a higher degree of reliability. Further, radio frequency channels which will be covered by a receiving area, system information on each of the radio frequency channels, and area information are stored so as to become associated with one another.