Unisono is Bach Hearing Aid's high-end family of products. Unisono delivers cutting-edge features and high performance. It incorporates both 128-band adaptive noise reduction and an adaptive feedback canceller for a complete high-end solution. Unisono's adaptive noise reduction preserves perceived speech levels without causing distortion. It monitors noise levels independently in 128 individual bands. This strategy also employs advanced psychoacoustic models to eliminate audible noise and reduce the amount of perceptible artifacts introduced by the noise reduction algorithms. Based on a feedback cancellation method, Unisono's adaptive feedback cancellation algorithm provides increased maximum stable gain unlike other feedback strategies. Additionally, it features rapid adjustment for dynamic feedback situations, immunity to tonal inputs and much more. In addition to these adaptive algorithms, Unisono's also supports the following features: Directional processing, cross fading between audio paths for click-free memory changes, 8-band graphic equalizer, 8 generic biquad filters, optional peak clipping, flexible compression adjustments, programmable tones for memory change and low battery indicators, wideband gain, and volume control. Adaptive noise reduction Adaptive feedback cancellation Soft acoustic fade between memory changes Directional processing High fidelity audio CODEC 20-bit audio precision 95 dB input dynamic range with HRX Headroom Extension 4 channel WDRC compression 8-band graphic EQ 8 biquadratic filters Drives zero-bias 2-terminal receivers 4 analog inputs 4 fully configurable memories with audible memory change indicator AGCo with variable threshold, time constants, and optional adaptive release 16 kHz or 8 kHz bandwidth Advanced battery power management 4 channel WDRC with fine control of crossover frequency placement AGC-O with adaptive release functionality