在中医学中，“闻”是四诊之一，即医生可以通过听声音和嗅气味来辅助诊断疾病。其中，对咳嗽声的观察尤为重要，因为它可以提供关于呼吸道的宝贵信息。本文将探讨如何通过闻诊所收集的信息来确定咳嗽是否由燥邪侵犯肺部所致。

首先，我们需要了解什么是燥邪以及它与咳嗽的关系。燥邪是指干燥的气候条件或环境因素对人体造成伤害的一种外感病邪。当燥邪侵袭人体时，常表现为口干舌燥、皮肤干燥、咳嗽气喘等症状。而咳嗽则是肺部受影响最重的一个表现，因为肺主气司呼吸，且喜润恶燥。因此，如果咳嗽的声音带有特殊的特征，可能提示着燥邪的存在。

那么，怎样通过闻诊来判断咳嗽声是否源自燥邪呢？以下是一些关键点：

1. 咳嗽频率：燥邪引起的咳嗽通常较为频繁，这是因为燥邪伤津，使得呼吸道缺乏滋润，导致气道敏感度增加，容易引起反射性的咳嗽反应。
2. 咳嗽音质：燥邪咳嗽的声音常常比较尖锐或者短促，这可能是因为干燥的环境下，气过玄关（喉咙）时会带起较小的颗粒物，这些物质摩擦气道壁发出尖锐的声音。同时，由于肺部水分不足，气体流动不畅，也会产生类似吹哨子的声音。
3. 咳嗽伴随症状：除了咳嗽本身，燥邪还可能导致其他不适，如咳嗽气喘的人群可能会感到嗓子干痒、咳嗽气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气喘气