Parametric investigation of the virtual glide
Nandini Iyer, Babette Eaton, Ramkumar Sridharan · The Journal of the Acoustical Society of America · 1999
This study examined the perceptual spectral integration effect using dynamic signals called ‘‘virtual glides’’ (Lublinskaya, 1996; Anantharaman et al., 1997). A virtual glide was generated by modulating the amplitude of two sinusoids at fixed frequencies (f1 and f2) which were centered at fc, with a frequency separation of Δf. Initially, the level of f1 was higher than the level of f2. Over the duration of the signal, the level of f1 decreased linearly while the level of f2 increased at the same rate. This produced the percept of a frequency glide; hence the name ‘‘virtual glide.’’ The subjects’ task was to match the rate of change of a real glide to that of a virtual glide using Jesteadt’s (1980) double staircase matching procedure. The fc, Δf, and duration of the stimuli remained constant within a block. The fc of the virtual glide was varied (500, 1000, 2000 Hz), as was Δf (2, 4, 5, 6, 8 ERB). Further, the stimuli were presented at three different durations (125, 250, 500 ms). The slope of the linear glide was varied adaptively to obtain the 50% point of subjective equality (PSE). We investigated the range of Δf and signal duration over which listeners could perform this task.