Group delay measurements from spiral ganglion cells in the guinea pig cochlea

Measurements of group delay were made extracellularly from spiral ganglion cells in the basal turn of the guinea pig cochlea, using sinusoidally amplitude modulated tones, with constant modulating frequency and modulation depth at the microphone input. Threshold cochlear tuning was accompanied by a frequency dependent group delay, with relative peak proportional to Q10. For sensitive units with steep intensity functions, the group delay decreased with increasing sound pressure level above threshold, without a significant change of Q10.