English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

To determine whether acoustical materials installed in Government buildings meet specifications of acoustical properties and to determine the effect of various methods of maintenance on the acoustical properties of acoustical materials, a modification of the familiar laboratory impedance tube has been adapted for field measurements of the absorption coefficient at 512 c.p.s. only. The absorption coefficient for reverberant sound is calculated on the basis of a semi‐empirical development described at the last meeting by A. London. The apparatus will be described and results of simulated field tests on several acoustic materials will be presented giving a comparison between the reverberation room measurement and the simulated field test as well as the standard deviation of several tests made on the same material. A means of allowing for the errors inherent in the method in calculating the absorption coefficient for reverberant sound will be indicated.

A Long-Tube Method for Field Determinations of Sound Absorption Coefficients