Filter banks are the major signal processing blocks that dissipate large amount of power in a portable digital hearing aid device. The power consumption can be reduced by replacing the power-hungry multipliers of the filter by power efficient approximate multipliers. This paper illustrates the application of an approximate multiplier for error tolerant hearing aid application. Frequency response masking approach is used for the development of a 10-band non-uniform approximate FIR filter bank with a minimum stop band attenuation of greater than 50 dB. Audiogram matching is done with audiograms of different types of moderate hearing loss and the matching error is computed. Simulation results show that the audiogram matching error falls within +/− 5 dB range.

滤波器组是主要的信号处理模块，可消耗便携式数字助听器设备中的大量功率。通过用高效节能近似乘法器代替滤波器的耗电乘法器，可以降低功耗。本文说明了近似乘数在容错助听器应用中的应用。频率响应屏蔽方法用于开发10频带非均匀近似FIR滤波器组，其最小阻带衰减大于50 dB。用不同类型的中度听力损失的听力图进行听力图匹配，并计算匹配误差。仿真结果表明，听力图匹配误差在+/- 5 dB范围内。