Six Nucleus cochlear implant recipients participated in a study investigating the effect of place of stimulation on melody perception using rate-pitch cues. Each stimulus was a pulse train delivered on either a single electrode or multiple electrodes sequentially. Four spatial stimulation patterns were used: a single apical electrode, a single mid electrode, a pair of electrodes (apical and mid), and 11 electrodes (from apical to mid). Within one block of trials, all stimuli had the same spatial stimulation pattern, with pulse rate varying from 131 to 262 pps. An additional pulse rate range of 262 to 523 pps was tested with the single-electrode stimuli. Two experimental procedures were used: note ranking; and a modified melodies test with backwards and warp modification. In each trial of the modified melodies test, a familiar melody and a version with modified pitch were presented (in random order), and the subject’s task was to select the unmodified melody. There were no significant differences in performance for stimulation on 1, 2, or 11 electrodes, implying that recipients were unable to combine temporal information from different places in the cochlea to give a stronger pitch cue. No advantage of apical electrodes was found: at the lower pulse rates, there were no significant differences between electrodes; and at the higher pulse rates, scores on the apical electrode dropped more than those on the mid electrode.

The present study compared pitch and melody perception using cochlear place of excitation and temporal cues in six adult nucleus cochlear implant (CI) recipients. The stimuli were synthesized tones presented through a loudspeaker, and recipients used the Advanced Combinational Encoder (ACE) sound coding strategy on their own sound processors. Three types of tones were used, denoted H3, H4, and P5. H3 tones were harmonic tones with fundamental frequencies in the range C3–C4 (131–262 Hz), providing temporal pitch cues alone. H4 tones were harmonic tones with fundamental frequencies in the range C4–C5 (262–523 Hz), providing a mixture of temporal and place cues. P5 tones were pure tones with fundamental frequencies in the range C5–C6 (523–1046 Hz), providing place pitch cues alone. Four experimental procedures were used: pitch discrimination, pitch ranking, backward modified melodies, and warped modified melodies. In each trial of the modified melodies tests, subjects heard a familiar melody and a version with modified pitch (in randomized order), and had to select the unmodified melody. In all four procedures, many scores were much lower than would be expected for normal hearing listeners, implying that the strength of the perceived pitch was weak. Discrimination and ranking with H3 and P5 tones was poor for two-semitone intervals, but near perfect for intervals of five semitones and larger. H4 tones provided the lowest group mean scores in all four procedures, with some pitch reversals observed in pitch ranking. Group mean scores for P5 tones (place cues alone) were at least as high as those for H3 tones (temporal cues alone). The relatively good scores on the melody tasks with P5 tones were surprising, given the lack of temporal cues, raising the possibility of musical pitch using place cues alone. However, the alternative possibility that the CI recipients perceived the place cues as brightness, rather than musical pitch per se, cannot be excluded. These findings show that pitch perception models need to incorporate neural place representations alongside temporal cues if they are to predict pitch and melody perception in the absence of temporal cues.

The current study aimed at obtaining and examining the normative tympanometric findings in the Chinese older adults (60 to 90 years). The tympanometric data was collected using the Interacoustics Titan IMP 440 clinical immittance meter. This included peak static acoustic admittance (Ytm); tympanometric peak pressure (TPP); tympanometric width (TW); and ear canal volume (ECV). 146 (228 ears) Chinese older adults with normal hearing or sensorineural hearing loss were included in the study. The mean and standard deviation of the tympanometric values include: Ytm 0.48±0.28mmho; TPP -5±11daPa; TW 74±27daPa; and ECV 1.06±0.29 cc. Factors such as ear, gender and age had a minimal effect on all the four-tympanometric parameters studied. Nevertheless, there were a few differences between the present study results and the previously published data. The study results warrant the need for population and age specific normative values for clinical use.

Cervical Vestibular Evoked Myogenic Potential (cVEMP) is a routine vestibular test which checks the integrity of vestibulocollic reflex (VCR)pathway