STANDARDS NEWS George Maling, Jr. IBM Acoustics laboratory, Poughkeepsie, New York 12602

Avril Brenig, Standards Manager ASA Standards Secretariat, Acoustical Society of America

335 East 45 Street, New York, New York 10017

American National Standards (ANSI Standards) in the area of physical acoustics, bioacoustics, and mechanical shock and vibration are published by the Acoustical Society of America (ASA). In addition to these standards, other Acoustical Society standards and an Index to Noise Standards-ASA STDS. Index 1-1976 (national and

international) are available from the Standards Secretariat of the Acoustical Society. To obtain a current list of standards available from the Acoustical Society, write to Avril Brenig, at the above address. Telephone number: (212) 661-9404.

Galloway is appointed ASA Standards Director Dr. William J. Galloway was appointed ASA Standards Director

at the meeting of the Acoustical Society held in Cambridge in June 1979. He is now also an ex officio member of the Executive Coun- cil.

Dr. Galloway succeeds Dr. Henning E. von Gierke, the first Standards Director, who is now President of the Society.

The ASA Standards Director position was 4reared in May 1978 following the Society's Committee on Standards (ASACOS) rec- ommendation to the Executive Council that such a post be estab- fished.

268-14A(1973): First supplement: Chapter II: Connecting devices. Section One: Circular connectors

for the interconnection of sound system components.

268-15(1978): Part 15: Preferred matching values for the interconnection of sound system compo- nents.

581-1(1977): High fidelity audio equipment and systems; Minimum performance requirements. Part 1: General.

581-3(1978): Part 3: Record playing equipment and car- tridges.

First International Standard for high fidelity amplifiers issued by I EC

The International Electrotechnical Commission (IEC) has an- nounced the availability of the first international standard giving minimum performance requirements for high fidelity amplifiers. It will be useful to all involved in the marketing and purchasing of am- plifiers: by consumers in building product confidence; by test houses when comparing equipment; and by manufacturers.

The standard is the latest in a series being developed by the inter- national body for high fidelity audio equipment and systems. Desig- nated Publication 581 series, part 6 and issued in August 1979, it provides minimum performance requirements for linear and equaliz- ing preamplifiers, power amplifiers and integrated amplifiers pri- marily intended for high quality reproducing systems in the home.

Publication 581-6 comprises two major sections. The first, titled "minimum requirements for characteristics directly related to the reproducing quality," covers for example, effective frequency range, gain alignment, total harmonic distortion, and rated output power. Other characteristics mentioned in this section include those related

to crosstalk attenuation (between stereo channels as well as inputs), wideband signal-to-noise ratio, and the weighted signal-to-noise ratio.

The second section is devoted to "other characteristics and re-

quirements." These include clauses on: balance control; loudness control; the marking of controls; mechanical and electrical intercon- nections; and characteristics to be specified in manufacturers' manu- als. The price of the document is SFr. 25.-. Contact the IEC, 1, me de Varemb•, 1211 GENEVA 20, Switzerland.

IEC recommends that this standard be used in conjunction with those already issued in the Publication 268 series as well as those others mentioned below for the electroacoustics field: They com- prise:

Publication Nos.

179(1973): Precision sound level meters 268-1(1968): Sound system equipment Part 1: General 268-1B(1972): Second supplement 268-3(1969): Part 3: Sound system amplifiers 268-3C(1978): Third supplement 268-14(1971): Part 14: Mechanical design features

Acoustical Society publishes two new sound power standards

In March 1970 the International Organization for Standardiza- tion (ISO) began work on a new series of standards to be used for measuring the noise emitted by machinery and equipment. The series of standards, all based on sound power, was produced by Subcommittee 1 (Noise) of ISO Technical Committee 43 on Acous- tics. Development of the standards was by Working Group 6, Noise Emitted by Machinery and Equipment.

Shortly there. after, American National Standards Committee S 1 began prepartion of a series of American National Standards cover- ing the same area, and American National Standard S1.21-1971 has been available for eight years. It is the current national counterpart of ISO 3741 and ISO 3742.

A series of seven standards has been under development within the S1 Committee, and the first two of the seven standards have been approved by the American National Standards Institute (See Standards News, September 1979) and are now available from the Society. Work on the five additional standards is proceeding rapid- ly, and ANSI approval of the remaining documents is expected be- fore the end of 1979.

American National Standard SI.30-1979 introduces the remain-

ing six standards which specify various methods for determining the sound power levels of machines and equipment. Guidelines for making decisions concerning the type of test and the specific details for mounting and operating the equipment are provided in the stan- dards. Also covered is a synopsis of each of the six standards which, when approved, will carry the designations ANSI S 1.31-S 1.36.

American National Standard S1.35-1979, Precision Methods for the Determination of Sound Power Levels of Noise Sources in Ane-

choic and Hemi-Anechoic Rooms contains information on micro-

phone arrays, instrumentation, installation and operation of a source, procedures for calculation of sound power level, directivity index, and directivity factor. Measurements made according to this standard must be performed in a laboratory environment. Other standards in the series cover measurement methods in a reverberent

environment, measurements in a free field, measurements in a spe- cial test room, and in situ measurements.

1566 J. Acoust. Soc. Am. 66(5), Nov. 1979 0001-4966/79/11 1566-02500.80 ¸ 1979 Acoustical Society of America 1566

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