Patent ID: 8535236

Claim:
A hardware apparatus for analyzing a sound signal, comprising: an ear model for deriving, for a number of inner hair cells, an estimate for a time-varying concentration of a transmitter substance inside a cleft between an inner hair cell and an associated auditory nerve from the sound signal, so that an estimated inner hair cell cleft contents map over frequency and over time is obtained, wherein the inner hair cells comprising lower order inner hair cells indicating lower frequencies and higher order inner hair cells indicating higher frequencies; and a pitch analyzer for analyzing the inner hair cell cleft contents map to obtain a pitch line over time, the pitch line indicating a pitch of the sound signal for respective time instants, wherein the pitch line varies in time over higher frequencies and lower frequencies as determined by the pitch analyzer; wherein the pitch analyzer further comprises a vibration period detector, the vibration period detector being operative for calculating a summary auto correlation function for each time period of a number of adjacent time periods using the estimates for the transmitter concentrations of the number of inner hair cells; wherein the vibration period detector is further operative, for each inner hair cell, to derive a time distance value T describing a time distance between two adjacent maxima in one estimate of the transmitter concentrations, and to enter a resulting time distance value T or a frequency value F derived from the time distance value T into a summary auto correlation function histogram, and wherein the ear model and the pitch analyzer are implemented using hardware or using a non-transitory computer readable medium storing computer instructions executable by a processor.