A method of determining a distance between a vehicle and a sound source includes detecting, at a microphone of the vehicle, sounds from a sound source external to the vehicle. The sounds have a first frequency component at a first frequency and a second frequency component at a second frequency. The method also includes determining, at a processor of the vehicle, a classification of the sound source based on audio properties of the sounds. The method further includes determining a first energy level associated with the first frequency component and a second energy level associated with the second frequency component. The method also includes determining a ratio between the first energy level and the second energy level. The method further includes determining the distance between the vehicle and the sound source based on the ratio and the classification of the sound source.

A blind spot information acquisition device includes: a processor configured to: acquire sounds in an area around a vehicle, infer positions of occurrence of the sounds that have been acquired, acquire information relating to objects in the area around the vehicle, and determine that there is a sound occurring in a blind spot in a case in which a sound source in the positions of occurrence of the sounds cannot be identified from the information relating to objects in the area around the vehicle that has been acquired.

An observation system includes: an observation device that includes an eyepiece lens and an objective and forms a real image of a sample on an optical path between the eyepiece lens and the objective; and an observation auxiliary device that is worn by a user and outputs auxiliary information to the user, the observation auxiliary device superimposing the auxiliary information on a virtual image of the sample to be observed by the user through the eyepiece lens on the basis of a relative position of the observation auxiliary device with respect to the observation device.

An observation system includes: an observation device that includes an eyepiece lens and an objective and forms a real image of a sample on an optical path between the eyepiece lens and the objective; and an observation auxiliary device that is worn by a user and outputs auxiliary information to the user, the observation auxiliary device superimposing the auxiliary information on a virtual image of the sample to be observed by the user through the eyepiece lens on the basis of a relative position of the observation auxiliary device with respect to the observation device.

The present invention relates to an underwater communication method capable of communicating with a plurality of sensor nodes within a limited frequency band. Underwater information communication of the present invention allocates an appropriate frequency to each sensor node according to the distance between a central node and the plurality of sensor nodes, and then, controls underwater communication between the central node and the plurality of sensor nodes using the allocated frequency. By virtue of such control, the present invention prevents the occurrence of an unusable sensor node which cannot smoothly perform underwater communication when the allocated frequency is unreasonable. Therefore, the present invention has the effect of enabling efficient underwater communication between a plurality of sensor nodes and a central node.

The present invention relates to an underwater communication method capable of communicating with a plurality of sensor nodes within a limited frequency band. Underwater information communication of the present invention allocates an appropriate frequency to each sensor node according to the distance between a central node and the plurality of sensor nodes, and then, controls underwater communication between the central node and the plurality of sensor nodes using the allocated frequency. By virtue of such control, the present invention prevents the occurrence of an unusable sensor node which cannot smoothly perform underwater communication when the allocated frequency is unreasonable. Therefore, the present invention has the effect of enabling efficient underwater communication between a plurality of sensor nodes and a central node.

A detection device and a detection system that detect a whistle sound to estimate the distance to the sound source are provided. The detection device (1) includes a detector (20) that detects a sound wave; storage (30) that contains characteristic information indicating frequencies of a fundamental and harmonics of a whistle sound and levels of the harmonics relative to the fundamental; a frequency analysis unit (41) that determines a frequency spectrum of a sound wave detected by the detector; a determination unit (45) that determines whether the frequency spectrum has peaks of the fundamental and the harmonics and how many times the peaks of the harmonics from the fundamental exceed a preset minimum level; and a distance estimation unit (46) that estimates a distance to a sound source of a whistle sound detected by the detector, based on a relationship between propagation distances and attenuations of a sound wave as well as information on the levels included in the characteristic information and the result of determination by the determination unit.

A detection device and a detection system that detect a whistle sound to estimate the distance to the sound source are provided. The detection device (1) includes a detector (20) that detects a sound wave; storage (30) that contains characteristic information indicating frequencies of a fundamental and harmonics of a whistle sound and levels of the harmonics relative to the fundamental; a frequency analysis unit (41) that determines a frequency spectrum of a sound wave detected by the detector; a determination unit (45) that determines whether the frequency spectrum has peaks of the fundamental and the harmonics and how many times the peaks of the harmonics from the fundamental exceed a preset minimum level; and a distance estimation unit (46) that estimates a distance to a sound source of a whistle sound detected by the detector, based on a relationship between propagation distances and attenuations of a sound wave as well as information on the levels included in the characteristic information and the result of determination by the determination unit.

Systems and methods for communicating information related to a wearable device are disclosed. Exemplary information includes audio information.

Systems and methods for communicating information related to a wearable device are disclosed. Exemplary information includes audio information.