Standards for a quieter world: Some acoustical reflections form the UK National Physical Laboratory

From the early days of serious scientific interest in noise, there was recognition of the vital importance to the process of noise control of standardization-of measuring instruments, measurement method s, of noise criteria. For more than 70 years, the National Physical Laboratory (NPL) has contributed to national and international standardization in the field of acoustics, and, through this process, NPL has, in my view, contributed to a quieter world. But, in an ironic way, the work has itself gone on quietly in the background. It therefore seemed appropriate, in view of the theme of INTER-NOISE 97 , to review, from my personal perspective, the contribution which NPL has made. The review is in two parts. The first covers the time from the origins of work on noise in the 1920s to the beginning of the 1970s, when [ started work at NPL, and the second the period since the 1970s. The main emphasis will be on specification standards, but reference will be made to key aspects of the work on metrological standards, which of course, through the realization of the basic standard of sound pressure, underp ins all acoustical measurements. The paper will not deal with the processes of standards development.