Amplitude-modulated sounds split into slow-varying envelope and fast-varying fine structure

Evidence

An amplitude-modulated sound is described in two parts: the envelope (or modulator), the portion of the stimulus that slowly varies over time, and the fine structure (or carrier), the portion of the stimulus with rapid pressure fluctuations. — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 997

Categorization

• DEFINE: Defines envelope/modulator versus fine structure/carrier in amplitude-modulated sounds.
• corroborated: 2 independent passages support this claim — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 997
• XREF: connects to: Intrinsic noise amplitude fluctuation masks detection of imposed amplitude modulation; Modulation frequency determines whether sound is heard as fluctuation, roughness, or multiple tones — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1217; Human hearing is highly nonlinear and cannot be LTI-modelled beyond peripheral parts (+8 more)

Broader Connections

• Rapid changes in a sound’s amplitude envelope force broader spectral bandwidth #expands (0.85) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 489
• Frequency-domain analysis mirrors how the human ear processes sound #expands (0.80) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 377
• Faster-fluctuating sounds trigger less cochlear compression, trading sensitivity for better dynamic encoding #expands (0.78) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3637
• Complex real-world sounds can be analyzed via Fourier analysis #expands (0.75) — David Howard, Jamie Angus, coustics and Psychoacoustics, 436
• Octave-band averaging can hide perceptually relevant acoustic variations #complicates (0.72)