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MMC Sound Creation

Fig. 8

Latch design requirements (for optimal time difference between sound elements)

4.3 Results of door-closing sound creation In accordance with the aforementioned conditions, the door latch was revised, with the result that the intended sound was achieved (Fig. 8). In Fig. 9, a conventional door-closing sound is compared with the newly proposed door-closing sound. Since the conventional development is to simply minimize sound, in the mechanism of door-closing sound, two aforementioned key sound elements (a) and (b) are totally different from each other and occur with too great a time interval between them. Thus the result is a flimsy and monotonous sound. With the newly proposed arrangement, two sound elements (a) and (b) have the same harmonics and occur with an optimal time interval between them, resulting in a refined mechanical sound.

Fig. 9

Conventional and newly proposed door-closing sounds

5. Evaluation by typical automobile users The newly proposed engine sound and door-closing sound were evaluated by 100 typical automobile users in a clinic as described below. (1) Clinic methodology (Fig. 10) Clinic participants listened to the engine sounds through headphones while watching a video of the view that they would see from the cabin of an accelerating automobile. Further, the participants listened to the door-closing sounds through headphones while watching a video of the door being closed. All participants were shown the same videos to ensure that their evaluations were not differently affected by different images. (2) Subjects used in comparisons (Fig. 11) We prepared the sounds of three typical competing vehicles.

Fig. 10


The results of the clinic showed that the newly proposed sounds were consistent with the intended ‘powerful and exciting’ positioning and that they were an extremely effective means of achieving differentiation from competing vehicles.



Normally, structures are designed to simply reduce noise to the greatest possible extent. In the research program described in this paper, by contrast, ‘powerful and exciting’ positioning was proposed for sound creation and the challenges of actively producing sound


MMC Sound Creation. Technical Review 2005  

The sound that a device emits when it is operated not only indicates that the device has been operated; it also plays a large role in convey...