In order to develop the practical ship's noise prediction method applicable on early design stage, at first, structure-borne sound transmission prediction of Janssen's method on which has been currently used was examined with the aim to improve and extend. Onboard vibration measurements on recent ships were carried out to verify the accuracy of the method. From their results, the prediction formula of the method was adapted and their coefficients of the parameters of each octave band frequency's which have never been obtained were decided. 2^nd, as the easy theoretical method which uses ship's sizes, shapes and structures, and is expected improvement of accuracies and effective for countermeasures, the SEA using the sectional ship's structure model was developed. Their calculated results were compared with measurements and good agreement with them. So, these methods of two stages are proposed as applicable methods on early design stage.

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In Japan, many sounds designed for the visually handicapped are not only useless, but also create noise for impaired and non-impaired people alike. Interview surveys with visually handicapped people were analyzed to reveal the types of inadequately designed barrier-free acoustic sounds and why they are not useful. The results indicated that inadequate barrier-free acoustic designs can be classified into at least six typical categories: (1) a sound level is too low, (2) a sound reverberates too much to enable orientation, (3) similar sounds are set up in the same neighborhood, (4) inappropriate announcements are made, (5) sounds are provided at inappropriate places or times, and (6) information about the sounds, for example where new sounds have been provided or what new sounds mean, is not distributed to visually-impaired people.

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Multivariate analysis was applied to vibration data measured at various construction sites using the Bornitz formula, and the measured data were put in order on the following basis: 1) Geometric attenuation coefficient n is adopted as 0.75, because approximate values are nearly equal in the two cases of geometric attenuation coefficient n=0.5 and n=0.75; 2) The attenuation coefficient α should be constant except for super high-frequency vibration hammer, because the number of measurements is insufficient to permit the subdivision of α by the construction categories and types of ground.

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