Abstract: A driving assistance device of an embodiment includes a recognizer configured to recognize a surrounding situation of a mobile object, a determiner configured to determine, on the basis of the surrounding situation, whether to prompt a driver of the mobile object to perform a steering operation and whether there is a possibility of a risk occurring for the mobile object, and a notification controller configured to cause a speaker to output a guidance sound prompting the driver of the mobile object to perform a steering operation and a warning sound with respect to the risk on the basis of a result of the determination by the determiner, in which the notification controller causes output modes for the guidance sound and the warning sound to be different from each other.

Abstract: According to an embodiment, a driving assistance device includes a recognizer configured to recognize a surrounding situation of a mobile object, a decider configured to decide whether or not to prompt a driver of the mobile object to perform acceleration or deceleration on the basis of the surrounding situation, and a notification controller configured to cause a speaker to output a notification sound for prompting the driver of the mobile object to perform the acceleration or deceleration on the basis of a decision result. The notification sound is a notification sound obtained by continuously changing a structure of a sound.

Abstract: A driving assistance device of an embodiment includes a recognizer that recognizes a surroundings situation of a vehicle, and a display controller that causes an image for assisting an occupant driving the vehicle to be displayed in a plurality of preset display modes on a display device, the plurality of display modes include display modes corresponding to at least a display mode corresponding to a mode in which the vehicle travels on a narrow road, and the display controller causes transition to any one of the plurality of display modes to be performed on the basis of the surroundings situation recognized by the recognizer.

Abstract: A driving assistance device includes a storage device storing a program and a hardware processor connected to the storage device. The hardware processor reads and executes the program stored in the storage device to recognize a risky physical object located near a mobile object on the basis of an output of a physical object detection device, cause at least one speaker to output a notification sound on the basis of a position of the risky physical object, and when the notification sound is output, cause the at least one speaker to output a first notification sound if the risky physical object is located in a first region including a region in front of the mobile object and cause the at least one speaker to output a second notification sound if the risky physical object is located in a second region including a region behind the mobile object. The first notification sound is a sound having a pitch different from that of the second notification sound.