Image-guided robotic surgery, designed for operating on small structures, is demonstrated for robotic cochlear implantation.

Objective.To compare hearing and speech understanding between a new, nonskin penetrating Baha system (Baha Attract) to the current Baha system using a skin-penetrating abutment.Methods.Hearing and speech understanding were measured in 16 experienced Baha users. The transmission path via the abutment was compared to a simulated Baha Attract transmission path by attaching the implantable magnet to the abutment and then by adding a sample of artificial skin and the external parts of the Baha Attract system. Four different measurements were performed: bone conduction thresholds directly through the sound processor (BC Direct), aided sound field thresholds, aided speech understanding in quiet, and aided speech understanding in noise.Results.The simulated Baha Attract transmission path introduced an attenuation starting from approximately 5 dB at 1000 Hz, increasing to 20–25 dB above 6000 Hz. However, aided sound field threshold shows smaller differences and aided speech understanding in quiet and in noise does not differ significantly between the two transmission paths.Conclusion.The Baha Attract system transmission path introduces predominately high frequency attenuation. This attenuation can be partially compensated by adequate fitting of the speech processor. No significant decrease in speech understanding in either quiet or in noise was found.

In this prospective multicenter study, tinnitus loudness and tinnitus-related distress were investigated in 174 cochlear implant (CI) candidates who underwent CI surgery at a Swiss cochlear implant center. All subjects participated in two session, one preoperatively and one 6 months after device activation. In both sessions, tinnitus loudness was assessed using a visual analogue scale and tinnitus distress using a standardized tinnitus questionnaire. The data were compared with unaided pre- and postoperative pure tone thresholds, and postoperative speech reception scores. 71.8% of the subjects reported tinnitus preoperatively. Six months after CI surgery 20.0% of these reported abolition of their tinnitus, 51.2% a subjective improvement, 21.6% no change and 7.2% a deterioration. Of the 49 (28.2%) subjects with no tinnitus preoperatively, 5 developed tinnitus 6 months after CI. These 5 had poorer speech understanding after CI surgery with their device than the group who remained tinnitus free. We found no correlation between tinnitus improvement, age, duration of tinnitus, or change in unaided hearing thresholds between the two sessions.

Objective: To investigate the effect of low-frequency attenuation of Bone-Anchored Hearing Aids (Bahas) in users with single-sided sensorineural deafness (SSD). The underlying notion is that low-frequency sounds up to approximately 1500 Hz reach the contralateral ear without significant attenuation and that Bahas tend to show more distortion at lower frequencies. Furthermore, to transmit low frequencies, higher moving masses are needed when compared with high frequencies. Design: A prospective study with 10 adults, experienced Baha Divino users with SSD. Speech understanding in noise was measured without Baha and with Baha, with three different settings of low-frequency attenuation, namely up to 270, 630, and 1500 Hz. Tests were performed in two different spatial arrangements. In one placement, speech was emitted from a loudspeaker on the side of the Baha ear and noise from a loudspeaker in front of the listener (S₉₀N₀). In the other placement, the sound sources were switched (S₀N₉₀). Participants rated the subjective sound quality of the two most extreme Baha settings using analog visual scales after a short acclimatization time of 15 mins. Results: In setting S₉₀N₀, the use of a Baha improved speech understanding in noise significantly (average improvement 2.8 to 3.1 dB, p = 0.006). These improvements did not vary significantly with the chosen low-frequency attenuation. In setting S₀N₉₀, a smaller but detrimental effect of the Baha was found (−0.9 to −1.7 dB, p = 0.006 to 0.03). This detrimental effect was significantly smaller at the highest cutoff frequency of 1500 Hz than at 270 Hz (p = 0.013). At the cutoff frequency of 270 Hz, loudness and reverberation were judged higher than at 1500 Hz. There was no significant difference in brightness, softness, clarity, or fullness. Conclusion: High cutoff levels of up to 1500 Hz for low-frequency signals do not compromise the benefit of Baha in SSD for noise arriving from the front and speech presented on the side of the Baha. If noise is presented from the side of the Baha, the detrimental effect on speech understanding can be reduced by higher cutoff frequencies. If frequencies <1500 Hz do not need to be transmitted, lower moving masses of the Baha are required and smaller devices for patients with SSD may be possible.

Adaptive beamformers have been proposed as noise reduction schemes for conventional hearing aids and cochlear implants. A method to predict the amount of noise reduction that can be achieved by a two-microphone adaptive beamformer is presented. The prediction is based on a model of the acoustic environment in which the presence of one acoustic target-signal source and one acoustic noise source in a reverberant enclosure is assumed. The acoustic field is sampled using two omnidirectional microphones mounted close to the ears of a user. The model takes eleven different parameters into account, including reverberation time and size of the room, directionality of the acoustic sources, and design parameters of the beamformer itself, including length of the adaptive filter and delay in the target signal path. An approximation to predict the achievable signal-to-noise improvement based on the model is presented. Potential applications as well as limitations of the proposed prediction method are discussed and a FORTRAN subroutine to predict the achievable signal-to-noise improvement is provided. Experimental verification of the predictions is provided in a companion paper [J. Acoust. Soc. Am. 109, 1134 (2001)].