Off-frequency tone detection benefits from envelope modulation cues produced by beating

Evidence

The narrowband noise masker has an envelope spectrum that predominantly has components in the range from 0 Hz to the masker bandwidth. Thus, the presence of an on-frequency tonal target signal does not substantially change this envelope spectrum. When, however, the tonal signal is presented off-frequency, new, higher-frequency spectral modulation components are introduced due to the beating between tone and masker that are only masked to a small degree by the inherent masker fluctuations. This modulation cue provides for an additional lowering of off-frequency monaural detection thresholds in excess of the peripheral filtering effect. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3463

This lack of a BMLD could be interpreted as a lack of effective binaural processing in off-frequency conditions. Alternatively, it could result from monaural processing which is much better in off-frequency as compared to on-frequency conditions. The narrowband noise masker has an envelope spectrum that predominantly has components in the range from 0 Hz to the masker bandwidth. Thus, the presence of an on-frequency tonal target signal does not substantially change this envelope spectrum. When, however, the tonal signal is presented off-frequency, new, higher-frequency spectral modulation components are introduced due to the beating between tone and masker that are only masked to a small degree by the inherent masker fluctuations. This modulation cue provides for an additional lowering of off-frequency monaural detection thresholds in excess of the peripheral filtering effect. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3466

Categorization

• DEFINE: Explains the mechanism whereby off-frequency beating between tone and narrowband masker introduces higher-frequency envelope cues detectable beyond peripheral filtering.
• XREF: Ties to modulation filterbank models and envelope-processing work (Dau et al. 1997; Nitschmann and Verhey 2012) the reader is building a mental model of. — connects to: Frequency-modulation detection relies on the steep lower excitation slope at 27 dB per Bark; Amplitude-modulated tones gain an extra detection cue that noise and FM tones lack
• corroborated: 7 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 3463; Dijk, Pim van, Physiology, Psychoacoustics and…, 3466