Using Concha Electrodes to Measure Cochlear Microphonic Waveforms and Auditory Brainstem Responses

Abstract

During electrocochleography, that is, ECochG or ECoG, a recording electrode can be placed in the ear canal lateral to the tympanic membrane. We designed a concha electrode to record both sinusoidal waveforms of cochlear microphonics (CMs) and auditory brainstem responses (ABRs). The amplitudes of CM waveforms and Wave I or compound action potentials (CAPs) recorded at the concha were greater than those recorded at the mastoid but slightly lower than those recorded at the ear canal. Wave V amplitudes recorded at the concha were greater than those recorded at the ear canal but lower than those recorded at the mastoid. There was not a significant difference between the amplitudes recorded at the concha and at the ear canal. For CM and Wave I or CAP, the latency recorded at the concha was longer than at the canal but shorter than at the mastoid; for Wave V, the reverse was true. However, these differences were not statistically significant and may be due to the distance to response generators. Aside from the advantages that the regular ECoG has over otoacoustic emission (OAE) testing, the concha electrode was also easier and safer to place and may be suitable for children, newborn screening, participants with canal conditions, and remote clinics which could have concerns with the availability and cost of a canal electrode. Using concha electrodes, we also experienced fewer postauricular artifacts than when using a mastoid electrode.

Hearing Assessment in Zebrafish During the First Week Postfertilization

“…In humans, cochlear microphonics are used to evaluate the functioning of the cochlea and its hair cells, which differs from the auditory brainstem recording assessment that is used to evaluate neural sensitivity to sound. 34 Adrien used the term ''cochlear microphonics'' in 1931 to describe recordings that Wever and Bray originally reported as neural responses from a cat's ear the year before. 35,36 Microphonic potentials are not limited to mammals and can be recorded from the inner ear of other vertebrates that do not possess the cochlea.…”

Using a Concha Electrode to Measure Response Patterns Based on the Amplitudes of Cochlear Microphonic Waveforms Across Acoustic Frequencies in Normal-Hearing Subjects

“…As such, interest in the development of an approach using noninvasive narrowband CM measurements is increasing. Some research has already been done which may facilitate the development of the CM approach in the assessment of cochlear functions (Zhang & Abbas 1993;Riazi & Ferraro 2008;Zhang 2010).…”

“…The development of approaches for using CMs may be paralleled or facilitated by the development of approaches of using different electrodes. For example, the development of an approach of using a concha electrode may be considered based on the fact that the canal electrode may have limitations under certain circumstances (Zhang 2010). For example, when the ear canal has infections or the ear canal is sensitive to touch, applying an electrode into the ear canal may become difficult.…”

“…Prior research has involved the use of a concha electrode in measuring CM waveforms (CMWs) at only one low frequency and not at the multiple or high frequencies (Zhang 2010). Other research has involved the use of a canal electrode rather than a concha electrode to measure response patterns of CM waveforms (Zhang 2012).…”

Response Pattern Based on the Amplitude of Ear Canal Recorded Cochlear Microphonic Waveforms across Acoustic Frequencies in Normal Hearing Subjects

“…One possible alternative is the application of cochlear microphonics (CMs). Both OAEs and CMs are cochlear responses (Dallos, 1981;Ferraro & Durrant, 2002;Kusakari et al, 1988;Norton, Ferguson, & Mascher, 1989;Ponton, Don, & Eggermont, 1992;Sun & Shaver, 2009), and as such, with sufficient research, using CM measurements may become an alternative approach to OAE measurements for assessing cochlear functions (Riazi & Ferraro, 2008;Zhang, 2010;Zhang & Abbas, 1993).…”