Gap detection for similar and dissimilar gap markers

Area of Science:

• Auditory Perception
• Psychoacoustics
• Signal Processing

Background:

• Temporal gap detection thresholds are typically higher for markers of dissimilar frequencies compared to similar frequencies.
• The underlying factors contributing to this threshold elevation, considering both spectral and temporal discontinuities, remain unclear.

Purpose of the Study:

• To investigate the influence of perceptual dissimilarities on auditory gap detection.
• To determine how spectral differences, including bandwidth, duration, and pitch, affect the ability to detect temporal gaps between auditory markers.

Main Methods:

• Experiment 1: Measured gap detection thresholds using narrow-band gap markers of pure tones, frequency-modulated (FM) tones, and amplitude-modulated (AM) tones.
• Experiment 2: Assessed gap detection with leading and trailing markers varying in bandwidth, duration, and pitch.

Main Results:

• Gap thresholds were elevated for frequency-disparate pure-tone markers compared to isofrequency markers.
• Perceptual discontinuities within the same frequency region did not consistently elevate thresholds.
• Gap detection worsened with differing marker bandwidths, even when spectral content was subsumed, indicating sensitivity to spectral dissimilarity.
• Marker duration effects were dependent on marker bandwidth; pitch differences between spectrally similar markers had no impact.

Conclusions:

• Auditory gap detection is sensitive to spectral dissimilarity between markers, not solely spectral discontinuity.
• Bandwidth differences between auditory markers significantly impair temporal gap detection.
• Pitch differences between spectrally similar markers do not affect gap detection thresholds.