Modification of Transmission Line Audible Noise Spectra to Reduce Environmental Impact

The aversiveness of audible noise from EHV electric transmission lines was evaluated for spectral modifications of 5 different tape-recorded samples. The relative contributions of low-frequency humming and buzzing and of high-frequency hissing and crackling components of the noise were determined. The high-frequency components of the hoise proved more aversive for all five samples to a group of 25 listeners. Therefore, for outdoor or open window listening, engineering efforts should be directed at reducing the high-frequency portion of the audible noise spectrum.