Time-frequency modulation and amplitude modulation are distinct operations

Evidence

Note that modulation as defined here is different from the amplitude modulation defined in Section 3.1.2. The modulation used in this chapter is realor complex-valued sinusoid, in contrast to amplitude modulation, where the sinusoidal modulator is defined to be positivevalued – a sinusoid offset by a positive value. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 2086

Categorization

• DEFINE: Draws a sharp line between two meanings of ‘modulation’ - a recurring terminological trap in audio DSP.