Headbands, Testbands and Softbands in Preoperative Testing and Application of Bone-Anchored Devices in Adults and Children

Abstract

The headbands, the testbands and the softbands are applied for coupling of the sound processors of the bone-anchored devices to the patient's head before the titanium fixture/abutment can be implanted. The bands are used for acute and/or prolonged testing of the bone-anchored devices, and are able to approximate the results of postoperative amplification. Yet, whatever the type of the band coupling, the transducers interface with the bone through a layer of skin and subcutaneous tissue that damp the transmission and decrease effective amplification. Therefore, the final hearing result with the bone-anchored device after implantation is usually better than with the sound processor attached to the headband, testband or softband, especially in the high-frequency zone. The results of our studies performed in experienced Baha Compact users quantified the magnitude of the skin damping and showed significant threshold differences for frequencies 1-4 kHz (in the range of 5-20 dB) when the Baha was coupled to the implanted fixture/abutment, as compared to the headband or the testband. These differences were also reflected in speech audiometry with the speech reception threshold improvement of approximately 4-7 dB. Suboptimal character of audiometric thresholds and speech understanding scores found during the preoperative testing period must be carefully considered in patient counseling, because such suboptimal results obtained preoperatively could demotivate the patients from using the Baha. Audiometrical results obtained with the headband and the testband are comparable; therefore, the more comfortable headband is also suitable for the preoperative audiological evaluation, especially in children.

Preoperative Headband Assessment for Semi-Implantable Bone Conduction Hearing Devices in Conductive Hearing Loss

“…Compared to published series, our results suggest that the siBCI may outperform pBCIs at higher frequencies, which is supported by Huber and Heywood (both of whom report results up to 6 kHz) (10,12), but not by Lassaletta, Tsang, or Zarowski, although these groups only measured thresholds up to 4 kHz (3,14,15). BC thresholds measurements above 4 kHz have been shown to be reliable, and we propose that they may be better able to predict functional outcomes for BCIs because many of the phonemes which make a major contribution to the intelligibility of speech (/f, t, s, th/) lie in the 4-to 8-kHz frequency range (18,19).…”

“…4), although this is by comparison with published data and would need to be confirmed experimentally. Although our cohort of patients had normal BC thresholds, the siBCI may also be a better option for hearing rehabilitation than a pBCI in patients with mixed hearing loss (MHL) whose BC threshold is raised in the high frequencies; in our series, aided thresholds at 4 kHz closely matched the bone curve, whereas reported data on pBCI performance suggests a reduction in hearing gain at 4 kHz and above (3,4,10). According to a large systematic review by Colquitt et al, PTA 4 functional gain for pBCIs ranges from 18 to 45 dB (11).…”

“…The main limitation of measuring hearing thresholds with a headband-mounted BCI processor is that some of the vibration energy is damped by the soft tissues which lie between the vibrator and bone, resulting in poorer transmission of sound. This effect seems to be more marked at higher frequencies, and affects both pure tone and speech audiometry (3).…”

Clinical Performance of a New Magnetic Bone Conduction Hearing Implant System

“…A possible improvement in hearing performance may be explained by adaptation as patients get used to the sound; it may also be an effect of fine-tuning of the SP by the audiologist. The fact that overall comparable outcomes were obtained with the SP on a softband as with the test device suggests that preoperative softband tests are a good predictor of the patient's postoperative hearing performance; the importance of preoperative testing to achieve successful clinical outcomes has been reported by several authors (5,28,29).…”

Bone anchored hearing aids in children: An update

“…The bone anchored hearing device on a headband is the gold standard for pre-operative assessment in children and can be used to predict the potential benefit of an implanted BAHD. The final hearing result with the bone-anchored device after implantation is usually better than with the sound processor attached to the headband [57]; the difference has been reported as much as 18 dB [58].…”