Detection of Deletion and Insertion of Tones in Bandlimited Noise

The detectability of insertion (TI) and deletion (TD) of tones in a noise background was compared. Tones of 500 Hz were gated on or off for 100 msec in noise with a spectrum level of 45 dB SPL. Psychometric functions were determined for two observers in a 21FC task under wideband and bandlimited conditions of the masking noise. Under all conditions, the following results were obtained: (1) TI is more detectable than TD by 3 dB or more; (2) the slope of P(c) vs E/N0 is greater for TD than for TI; and (3) the release from masking obtained with bandlimiting of the noise masker is greater for TD than for TI. The relationships of the present data to those of earlier studies and to critical band data are discussed.