A notification apparatus comprising: a first signal converter disposed in a cushion of a seat and configured to detect a vibration transmitted to the seat and to convert the vibration into a seat vibration signal; and a second signal converter disposed in a position other than the cushion of the seat and configured to detect a transmitted vibration and to convert the vibration into an input vibration signal; the notification apparatus is characterised in that it further comprises: a level difference calculator configured to acquire the seat vibration signal from the first signal converter, to acquire the input vibration signal from the second signal converter, and to calculate a signal level difference ΔG by subtracting a value of a level of the seat vibration signal from a value of a level of the input vibration signal; a notification aspect determination unit configured to determine a notification aspect for making a notification to a user, on the basis of a value of the signal level difference ΔG calculated by the level difference calculator; and a notification execution unit configured to, when acquiring notification information outputted when a notification situation detector detects a situation about which a notification is made, make the notification on the basis of the notification aspect determined by the notification aspect determination unit. a first signal converter disposed in a cushion of a seat and configured to detect a vibration transmitted to the seat and to convert the vibration into a seat vibration signal; and a second signal converter disposed in a position other than the cushion of the seat and configured to detect a transmitted vibration and to convert the vibration into an input vibration signal; the notification apparatus is characterised in that it further comprises: a level difference calculator configured to acquire the seat vibration signal from the first signal converter, to acquire the input vibration signal from the second signal converter, and to calculate a signal level difference ΔG by subtracting a value of a level of the seat vibration signal from a value of a level of the input vibration signal; a notification aspect determination unit configured to determine a notification aspect for making a notification to a user, on the basis of a value of the signal level difference ΔG calculated by the level difference calculator; and a notification execution unit configured to, when acquiring notification information outputted when a notification situation detector detects a situation about which a notification is made, make the notification on the basis of the notification aspect determined by the notification aspect determination unit. a level difference calculator configured to acquire the seat vibration signal from the first signal converter, to acquire the input vibration signal from the second signal converter, and to calculate a signal level difference ΔG by subtracting a value of a level of the seat vibration signal from a value of a level of the input vibration signal; a notification aspect determination unit configured to determine a notification aspect for making a notification to a user, on the basis of a value of the signal level difference ΔG calculated by the level difference calculator; and a notification execution unit configured to, when acquiring notification information outputted when a notification situation detector detects a situation about which a notification is made, make the notification on the basis of the notification aspect determined by the notification aspect determination unit.