Suprathreshold Perception of Tonal Components in Noise Under Conditions of Masking Release

Abstract

Many technical sounds contain tonal components in a noise background. The present study investigates how such tonal components embedded in noise are perceived under conditions of enhanced detectability of the tone due to (i) amplitude modulation of the noise background or (ii) interaural disparities in the signal's phase. To quantify the sensation elicited by a tonal component in these masking-release conditions, the listeners are asked to adjust the level of the tone to have the same magnitude of tonal content (German “Tonhaltigkeit”) or to be perceived as equally loud as a tone which is masked by an unmodulated noise and presented diotically (baseline condition). For both sensations the signal-to-noise ratio at equal magnitude of the sensation is lower for the tone in the masking-release conditions than for the baseline condition. This is mainly due to the lower masked threshold of the tone in masking-release conditions. The eff ect is most prominent at low levels and decreases towards higher levels. A high correlation is observed between the data for the magnitude of tonal content and the partial loudness of the tone, demonstrating the similarity between these two sensations.