Noise-canceling headphones from Sennheiser are always equipped with active noise-canceling technology. There are also noise-isolating or noise-reducing headphones on the market, which only provide passive noise reduction. Noise-isolating and noise-reducing headphones do not contain the same technology and only protect from ambient noise through the construction of the headphones.
例如,包耳式耳機能完全覆蓋耳朵,有助隔絕環境噪音。入耳式耳機則直接置於耳道內,因此使用者感知到的環境噪音較少。然而,隔音耳機始終存在聽力損傷的風險——例如當聽者為掩蓋背景噪音而將音樂音量調得過高時。