Partial deafness cochlear implantation provides benefit to a new population of individuals with hearing loss

Abstract

Hearing was preserved in 9 of 10 cases. One subject uses a hearing aid to amplify low frequency hearing, the remainder use natural low frequency hearing. Improvements in monosyllabic scores over time in both quiet and noise were significant, particularly within the first 3 months of PDCI use.

Cochlear implants: Current designs and future possibilities

“…Various surgical techniques and drug therapies have been developed to preserve low-frequency hearing in an implanted cochlea, including (1) deliberately shallow insertions of the electrode array (6, 10, 16, or 20 mm) so as not to damage the apical part of the cochlea and remaining hair cells there, (2) insertion of the electrode array through the round window membrane rather than through a cochleostomy to eliminate deleterious effects of drilling (loud and possibly damaging levels of noise, introduction of blood and bone dust into the perilymph, possible damage to delicate cochlear structures such as the BM), (3) use of "soft surgery" techniques to minimize trauma, (4) use of thin and highly flexible electrodes, (5) use of a lubricant such as hyaluronic acid to facilitate insertion of the array, and (6) use of corticosteroids and other drugs to help preserve cochlear structures in the face of surgical manipulations and the introduction of a foreign body into the inner ear. Moderate-to-excellent preservation of residual hearing has been reported for a majority of patients using the shallow insertions and some or all of the additional procedures and techniques just mentioned [93][94][95][96][97][98][99][100][101][102][103][104][105][106][107], although residual hearing is still completely lost for some patients with the same insertions and approaches. Among the tested methods, insertion through the round window for placement of 20 mm arrays or use of shorter arrays appear to be especially effective [103,106,[108][109].…”

“…(This ability is nonexistent or almost nil with a unilateral implant.) Combined EAS also provides a substantial benefit for listening to speech in quiet, in noise, or in competition with multitalker babble compared with either electric or acoustic stimulation alone [63,[93][94][96][97]99,[101][102][103][104][105][134][135][136][137][138][139][140]. Indeed, in some cases, the score for combined EAS is greater than the sum of the scores for the electric-and acoustic-only conditions.…”

Acoustic–electric interactions in the guinea pig auditory nerve: Simultaneous and forward masking of the electrically evoked compound action potential

“…Clinical studies indicate that it is possible to take advantage of residual acoustic hearing in these cases for better speech comprehension -especially in noisy environments -and improved aesthetic quality of perceived sounds (von Ilberg et al, 1999;Gstoettner et al, 2006;Turner et al, 2004;Kiefer et al, 2005;Gantz et al, 2006;Skarżyński et al, 2006). This can be achieved by employing combined electric and acoustic stimulation (EAS) of the auditory periphery with a CI and a hearing aid.…”

Hearing preservation surgery: Psychophysical estimates of cochlear damage in recipients of a short electrode array

“…A successful surgical outcome allows for an electric stimulation of basal neural tissue without damaging the apical cochlear structures that transmit low-frequency acoustic information ͑e.g., von Ilbert et al, 1999;Skarzynski et al, 2004Skarzynski et al, , 2006Skarzynski et al, , 2007Turner, 2003, 2004;Gstoettner et al, 2004;Gantz et al, 2005Gantz et al, , 2006Kiefer et al, 2005;Leutje et al, 2007͒. The mean hearing loss following this procedure ranges from 10 to 20 dB depending on the electrode array and the nature of the surgical technique ͑Gantz and Turner, 2004; Gantz et al, 2005;Skarzynski et al, 2003Skarzynski et al, , 2006Skarzynski et al, , 2007Gstoettner et al, 2004Gstoettner et al, , 2005Kiefer et al, 2005͒. The combination of binaural low-frequency acoustic hearing and monaural highfrequency electric hearing-termed combined electric and acoustic stimulation ͑EAS͒-has been shown to improve speech understanding in quiet and in noise beyond that achieved by aided acoustic or electric hearing alone ͑Wilson et al, 2002;Brill et al, 2002;Gantz et al, 2005;Gstoettner et al, 2004͒.…”