The brain measures interaural delay via coincidence-detector neurons and delay-line axons

Evidence

The majority of the binaural processing algorithms are based on the coincidence detection model proposed by Jeffress (1948). The model suggests that certain neurons in the brain are narrowly tuned to specific ITDs between the ear canal signals. As illustrated in Figure 13.13, the model consists of an array of coincidence-detector neurons receiving excitatory signals from both ears, and delay lines are used to represent axons connecting the neuron to the cochlear nuclei of the left and right ears. The highest activity is then received from the coincidence-detector neuron where the propagation delay in the inputs effectively cancels out the ITD between the left and right ear inputs. — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1662

Categorization

Category: Definitional Content

• DEFINE: Explains the canonical Jeffress coincidence-detection mechanism for ITD coding.
• XREF: This is a seminal mechanism that reappears in machine-listening models and neural delay-line literature.

Related

• The 1948 Jeffress model explains ITD coding via neural delay-line coincidence detectors (similarity 0.93)
• Jeffress coincidence detection explains how neurons encode interaural time differences. (similarity 0.92)
• Interaural time differences are computed by cross-correlating the two ear signals (similarity 0.90)
• Interaural time difference maps derive from precise phase delays, not absolute latencies (similarity 0.87)
• The ear detects binaural delays finer than individual neuron timing supports (similarity 0.85)
• Systematic conduction delay changes along the nucleus laminaris axis encode interaural time difference maps (similarity 0.82)
• Interaural correlation-change detection is a viable temporal processing measure (similarity 0.81)
• Humans can detect interaural timing differences as small as ten to twenty microseconds (similarity 0.81)
• The auditory system uses coarse physical delay lines plus fine phase-based matching for ITD (similarity 0.81)
• The periodic ringing of cochlear inputs sustains phase-based ITD coding for nonperiodic sounds (similarity 0.81)
• Just-noticeable interaural delay is about 50 microseconds below 1.5 kHz (similarity 0.81)
• Interaural phase differences can produce time-delay sensations measured at threshold. (similarity 0.81)
• Microsecond ITD precision arises from phase-delay matching, not absolute latency (similarity 0.81)
• The ear resolves low-frequency direction by measuring phase shift (similarity 0.80)
• Interaural-delay-tuned channels exist only for frequencies below 1500 Hz (similarity 0.80)

Broader Connections

• Interaural delay estimation is emulated mathematically by the normalized cross-correlation function #exemplifies (0.78) — Ville Pulkki, Matti Karjalainen, Communication Acoustics- An…, 1665