Brief tone pips were used as stimuli in two‐signal interference experiments to provide a basis for interpretation of intensity functions. Whole nerve action‐potential responses were recorded from the cochlea (guinea pig). Stimulation by a 6‐kcps pip interferes with the response to a 2‐kcps pip only when the latter reaches a magnitude (baseline peak measure) of 30–40μV, about 18 dB above a just detectable response. Interference depends more upon the strength of the 2 kcps pip than upon the strength of the 6‐kcps pip. The form of intensity functions for low‐frequency signals is dominated by a basal extension of excitatory region. Intensity functions for high‐frequency signals show less spatial change. The data suggest that there are tworesponse modesfor neural activity elicited by acoustic signals. For high‐frequency signals, synchrony of excitation depends upon envelope and there is little change in location of excitatory region along the cochlear partition with signal strength. For low‐frequency signals, synchrony depends upon the locations along the cochlear partition that exceed a critical amplitude, i.e., upon the velocity of the traveling wave. Broad‐band transient signals, such as clicks, may elicit neural activity in both response modes.