Headbands, testbands and softbands in preoperative testing and application of bone-anchored devices in adults and children

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.