Nicholas P. Chotiros
Morris Stern
Appl. Res. Labs., Univ. of Texas at Austin, P.O. Box 8029, Austin, TX 78713-8029
A full wave acoustic propagation model in a stratified viscoelastic medium [H. Schmidt and F. B. Jensen, J. Acoust. Soc. Am. 77, 813--825 (1985)] was combined with Biot's theory for propagation and reflection in a porous medium [Stern et al., J. Acoust. Soc. Am. 77, 1781--1788 (1985)] to produce a model of acoustic propagation in a stratified porous medium. Sample results were compared with a normal mode model [T. Yamamoto, J. Acoust. Soc. Am. 73, 1587--1596 (1983)]. The model was extended to account for the effect of gas bubbles in the pore fluid [J. A. Hawkins and A. Bedford, J. Acoust. Soc. Am. Suppl. 1 88, S131 (1990)]. Significant differences between viscoelastic, poroelastic, and gassy poroelastic models were investigated. [Work supported by ONR.]
Standards Committee S3 on Bioacoustics. The current status of standards under preparation will be discussed. In addition to those topics of interest, including hearing conversation, noise, dosimeters, hearing aids, etc., consideration will be given to new standards which might be needed over the next few years. Open discussion of committee reports is encouraged. The international activities in ISO/TC 43 Acoustics, and IEC/TC 29 Electroacoustics, and ISO/TC 108/SC 4 Human Exposure to Mechanical Vibration and Shock, will also be discussed. The chairs of the U.S. Technical Advisory Groups for ISO/TC 43 (H. E. von Gierke), and IEC/TC 29 (V. Nedzelnitsky), will report on current activities of these Technical Committees and Subcommittees. Reports will be given on preparations for the next meetings of ISO/TC 43 (in Oslo, Norway, from 31 May to 4 June 1993), and of IEC/TC 29 (in Oslo, Norway, from 24 to 28 May 1993). A report will be given on the ISO/TC 108/SC 4 meeting held in London, United Kingdom, from 29 March to 1 April 1993.
Standards Committee S1 on Acoustics. Working group chairs will report on their preparation of standards on methods of measurement and testing, and terminology, in physical acoustics, electroacoustics, sonics, ultrasonics, and underwater sound. Work in progress includes measurement of noise sources, noise dosimeters, integrating sound-level meters, and revision and extension of sound level meter specifications. Open discussion of committee reports is encouraged. The international activities in ISO/TC 43 Acoustics, and IEC/TC 29 Electroacoustics, will also be discussed. The chairs of the respective U.S. Technical Advisory Groups for ISO/TC 43 (H. E. von Gierke), and IEC/TC 29 (V. Nedzelnitsky), will report on current activities of these Technical Committees. Reports will be given on preparations for the next meetings of ISO/TC 43 (in Oslo, Norway, from 31 May--4 June 1993), and of IEC/TC 29 (in Oslo, Norway, from 24--28 May 1993).