Apple grove 750 KV project - two year statistical analysis of audible noise from conductors at 775 KV and ambient noise data

Abstract
This second paper on audible noise from Apple Grove 750 kV Test Project presents the results of a statistical analysis covering approximately two years of data on corona generated audible noise from three test lines. Also, statistical data is given on ambient noise in foul and fair weather, along with day-night variations. A comparison of measurements of audible noise from three sizes of four conductor bundles (diameter of 1.387 inch (35.1 mm), 1.196 inch (30.4 mm) and 1.0 inch (25.4 mm)) with measurements of ambient noise indicates the difference between the corona noise and background levels.