Natura Digital Hearing Instrument Mimi Farah The technology behind the Natura digital instrument is based on a nonlinear model of the human ear and is specifically designed to compensate for outer hair cell pathology. The DSP chip contains nine (9) independent compression channels allowing more precise control over the frequency and amplitude responses. Programming is carried out at ? octave intervals across the frequency range from 500 to 6000 Hz, and adjustments can be made within 1dB of the prescribed targets. The Natura uses expansion technology to de-emphasise low-level background noise occurring below the kneepoint, and thus reduce the risk of over-amplifying low intensity environmental sounds which is so typical of WDRC amplification. The expansion ratios and kneepoints vary by frequency across the nine narrow bands. By utilising fast acting attack and release times over the nine narrow-band channels, the aid is able to respond to speech cues and other sounds in real time, without a delay. As such, the problems of 'pumping' and spectral smearing are avoided. The Natura is suitable for a variety of hearing impairments ranging from very a mild to a severe loss, and is available in all models including CIC, ITC, ITE, and BTE. The EXPRESSfit fitting software allows for in-situ verification of the wearer's dynamic range and precise adjustment of the gain levels for the soft (50dB) and loud (90dB) input curves. Programming can be conducted either by using the PalmPilotO, which is a portable, hand-held personal computer, or by the NOAH based program. |