中文摘要：

由于听障患者的言语可懂度和声品质在噪声环境中严重下降，需在数字助听器中使用降噪技术以改善听障患者的言语感知效果。本文介绍了一般场景中的助听器降噪技术，包括单通道降噪技术和多通道降噪技术；然后介绍了特殊场景中的5种降噪技术，包括啸叫抑制技术、有源降噪技术、风噪抑制技术、混响抑制技术和动态压缩技术。本文对这些技术的原理、方法和性能进行了逐一分析，并列举了评估助听器降噪性能的主观指标和客观指标。最后对助听器降噪技术的发展趋势作了进一步展望。

英文摘要：

Since the speech intelligibility of hearing-impaired listeners deteriorates seriously in a noisy environment, it is necessary to use noise reduction technologies in digital hearing aids to improve speech perception of hearing-impaired listeners. This paper introduces the primary noise reduction technologies in hearing aids, including single-channel noise reduction and multi-channel noise reduction. Due to different application sceneries, five techniques are introduced, including howling suppression, adaptive noise control, wind noise reduction, dereverbration techniques and dynamic compression. Subjective and objective measures of noise reduction are introduced. Finally, the development of noise reduction technologies in hearing aids is given as future prospects.