ON Semiconductor's Rhythm™ SB3229 hybrid is a trimmer-configurable DSP system based on a four-channel compression circuit featuring a feedback cancellation algorithm.
Based on a phase cancellation method, Rhythm SB3229's adaptive feedback reduction algorithm provides added stable gain to enable extra gain and user comfort. It features rapid adjustment for dynamic feedback situations and resistance to tonal inputs.
In addition to these adaptive algorithms, Rhythm SB3229 also supports the following features: up to four channel WDRC, low-distortion compression limiting, cross fading between audio paths for click-free memory changes, eight-band graphic equalizer, eight configurable generic biquad filters, programming speed enhancements, in-channel squelch to attenuate microphone and circuit noise in quiet environments, optional peak clipping, flexible compression adjustments, volume control, rocker switch, noise generation for tinnitus treatment, and industry-leading security features to avoid cloning and software piracy.
A trimmer interface supports manual circuit configuration. It continuously monitors trimmer positions and translates them into the hearing-aid parameters of choice. A serial data or I²C interface provides full programmability at the factory and in the field.
The Rhythm SB3229 hybrid contains a 256 kbit EEPROM intended for programmable and trimmer based devices.
Software Support
ARK is a set of software building blocks that can help reduce the time it takes to develop hearing aid fitting software. ARKonline is an efficient web-based tool for creating product libraries and keeping them organized. To access ARKonline, please go to
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• Adaptive feedback cancellation
• WDRC compression with choice of 1, 2 or 4 channels of compression
• Auto telecoil with programmable delay
• EVOKE Lite™ acoustic indicators
• Noise generator for tinnitus treatment or in-situ audiometry
• Frequency response shaping with graphic EQ
• Trimmer compatibility - four three-terminal trimmers with configurable assignments of control parameters
• I²C and SDA programming
• Rocker switch support for memory change and/or volume control adjustment
• Analog or digital volume control with programmable range
• High quality 20-bit audio processing
• High power/high gain capability
• SOUNDFIT® fitting software
• Configurable low battery indicator
• Eight biquadratic filters
• 16 kHz or 8 kHz bandwidth
• Four fully configurable memories with audible memory change indicator
• 96 dB input dynamic range with HRX™ Headroom Extension
• 128-bit fingerprint security system and other security features to protect against device cloning and software piracy
• High fidelity audio CODEC
• Soft acoustic fade between memory changes
• Drives zero-bias two-terminal receivers
• E1 RoHS compliant hybrid