Frequency modulation detection depends on both carrier and modulation frequency.

Evidence

The JND of frequency depending on the frequency of the tone was shown earlier in Figure 10.2. Often, the frequency of continuous sound changes with time and varies around a centre frequency. The changing of frequency may or may not be audible as a change in pitch or some other perception. This change in frequency can be studied using frequency modulation. The JND of frequency modulation of carrier tones at different frequencies is shown as a function of modulation frequency in Figure 10.7. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1104