The effect of direction of background noise, background noise type, and signal type on the acceptable noise level in individuals with normal hearing

Abstract

Acceptable Noise Levels (ANLs) were examined for 19 participants with normal hearing using three types of stimuli (speech, music, phone ring) presented in the sound field at 0 degrees and two types of noise (babble, white noise) presented in the sound field via three different direction conditions: 0 degrees only, 180 degrees only, and surround (0 degrees, 90 degrees, 180 degrees, 270 degrees). Results showed no significant differences in ANLs across noise type or stimulus type, but a significant difference for surround sound loudspeaker array compared with speakers from one direction, with a larger ANL associated with multiple loud speakers. The main conclusion was that an individual's tolerance for background noise is not affected by signal type or type of background noise but is affected by the direction of the noise source.