Spectra for ensemble spontaneous activity recorded from Electrode B for the three animals for which histology is shown in Fig. 3. A peak in the spectrum near 900 Hz (-29.7 dB re 1 V) is typical of animals with residual acoustic hearing and presumed spontaneous activity in the auditory nerve (See Kang et al., 2010: mean = -33.4 dB, s.d. = 1.84, n = 11). The lack of a distinct peak and the low potentials (max -42.9 dB) near 900 Hz in the deaf animal is also similar to data reported previously (Kang et al., 2010: mean = -44.4 dB, s.d. = 2.5, n = 4). The intermediate voltage (-40.6 dB) recorded for the Deaf + AAV.NTF-3 treated animal is similar to that found in four other animals that were treated with neomycin followed by AAV.NTF-3 (unpublished results: mean = -41.1 dB, s.d. = 2.2 , n = 4).