Speech Understanding and Sound Localization with a New Nonimplantable Wearing Option for Baha.

OBJECTIVE: To measure the audiological benefit of the Baha SoundArc, a recently introduced nonimplantable wearing option for bone conduction sound processor, and to compare it with the known softband wearing option in subjects with normal cochlear function and a purely conductive bilateral hearing loss. METHODS: Both ears of 15 normal hearing subjects were occluded for the time of the measurement, yielding an average unaided threshold of 49 dB HL (0.5 - 4 kHz). Soundfield thresholds, speech understanding in quiet and in noise, and sound localization were measured in unaided conditions and with 1 or 2 Baha 5 sound processors mounted on either a softband or a SoundArc device. RESULTS: Soundfield thresholds and speech reception thresholds were improved by 19.5 to 24.8 dB (p<.001), when compared to the unaided condition. Speech reception thresholds in noise were improved by 3.7 to 4.7 dB (p<.001). Using 2 sound processors rather than one improved speech understanding in noise for speech from the direction of the 2nd device and sound localization error by 23° to 28°. No statistically significant difference was found between the SoundArc and the softband wearing options in any of the tests. CONCLUSIONS: Bone conduction sound processor mounted on a SoundArc or on a softband resulted in considerable improvements in hearing and speech understanding in subjects with a simulated, purely conductive, and bilateral hearing loss. No significant difference between the 2 wearing options was found. Using 2 sound processors improves sound localization and speech understanding in noise in certain spatial settings.

Unilateral and Bilateral Audiological Benefit With an Adhesively Attached, Noninvasive Bone Conduction Hearing System.

OBJECTIVE: To assess the audiological benefit of a noninvasive, adhesively attached bone conduction device (BCD1) in subjects with induced bilateral conductive hearing loss. Secondary objectives were to evaluate the additional benefit of bilateral fitting compared with unilateral fitting and to compare the outcomes with bone conduction devices attached to a softband (BCD2). STUDY DESIGN: Prospective nonrandomized crossover study. SETTING: Tertiary referral center. PATIENTS: Fifteen subjects with induced bilateral conductive hearing loss. MAIN OUTCOME MEASURES: Sound field thresholds, speech understanding in quiet and in multinoise were assessed in unaided, unilateral, and bilateral treatment conditions. In addition, sound localization was evaluated in uni- and bilateral treatment conditions. RESULTS: The outcomes of BCD1 and BCD2 were comparable. Sound field thresholds improved by 24.6 dB (BCD1) and 24.8 dB (BCD2) in the unilateral and 26.8 dB (BCD1) and 25.1 dB (BCD2) in the bilateral treatment condition. Speech reception thresholds (SRTs) in quiet improved by 20.0 dB (BCD1) and 21.7 dB (BCD2) in the unilateral and by 22.7 dB (BCD1) and 21.5 dB (BCD2) in the bilateral condition. If speech was presented from the front, SRTs in noise were improved by 3.6 dB and 4.2 dB (unilateral) and by 4.5 dB and 4.4 dB (bilateral) for BCD1 and BCD2, respectively. With speech presented from the unilateral side, SRTs were improved by 4.0 dB and 4.7 dB (unilateral) and 3.8 dB and 4.8 dB (bilateral) compared with the unaided situation. If noise was presented from the contralateral side, small differences (-0.6 dB and -0.1 dB) were observed. Bilateral fitting brought additional benefits for speech understanding in noise and sound localization. CONCLUSIONS: Both bone conduction devices seem to be a valid treatment for patients with conductive hearing loss and minor sensorineural hearing loss component.