To improve precision in voice recognition even when different noise components and levels are generated due to the changes in vehicle running speed.

The system is provided with a voice recognition means 22 which recognizes uttered words and phrases of a user, a vehicle speed sensor 25 which obtains vehicle speed information and a noise control means 37 of a CPU35 which obtains amount of noise inside and outside the vehicle based on the obtained speed information and adds the obtained amount of noise to comparison object vocabulary of voice recognition dictionary word data read from a disk 28. The means 22 conducts voice recognition by comparing the comparison object vocabulary to which noise from the means 37 is added and the uttered words and phrases of the user inputted from a microphone 36.