Dominant region for pitch at low fundamental frequencies (F0): The effect of fundamental frequency, phase and temporal structure

Abstract

When a complex tone contains many harmonics, its pitch is usually determined by harmonics in a restricted frequency region, called the “dominant region,” which for fundamental frequencies (F0s) ≥ 100 Hz corresponds to low, resolved harmonics. We estimated the dominant region for tones with low F0, by measuring thresholds, F0DLs, for detecting a change in F0 of a group of harmonics embedded within harmonics with fixed F0. The spectral position of the shifted group was systematically varied. Components were added in either cosine or random phase. For F0s of 35 and 50 Hz, the position of the dominant region depended strongly on the relative phases of the components. When the envelope had a low peak factor, with multiple peaks per period (random phase), the dominant region fell at low harmonic numbers (for F0=50 Hz), or was not well defined (for F0=35 Hz). When the envelope had a high peak factor, with one peak per period (cosine phase), the dominant region fell at high harmonic numbers, where harmonics were unresolved. Generally, performance was better for cosine than for random phase. The results indicate that harmonics in the dominant region are not always resolved.