Should medicine be used to enhance—not just restore—human bodies?

 

The Economist 

最愛  · 5分鐘  · 

This week on “Babbage”, using technology to improve humanity is no longer science fiction

economist.com

 Should medicine be used to enhance—not just restore—human bodies?1

骨傳導Bone conduction

Bone conduction is the conduction of sound to the inner ear primarily through the bones of the skull, allowing the hearer to perceive audio content even if the ear canal is blocked. Bone conduction transmission occurs constantly as sound waves vibrate bone, specifically the bones in the skull, although it is hard for the average individual to distinguish sound being conveyed through the bone as opposed to the sound being conveyed through the air via the ear canal. Intentional transmission of sound through bone can be used with individuals with normal hearing—as with bone-conduction headphones—or as a treatment option for certain types of hearing impairment. Bones are generally more effective at transmitting lower-frequency sounds compared to higher-frequency sounds.

Bone conduction is also called the second auditory pathway and not to be confused with cartilage conduction, which is considered the third auditory pathway.

 骨傳導是一種聲音傳導方式，即通過將聲音轉化為不同頻率的機械振動，通過人的顱骨、骨迷路、內耳淋巴液傳遞、柯蒂氏器、聽神經、聽覺中樞來傳遞聲波。相對於通過振膜產生聲波的經典聲音傳導方式，骨傳導省去了許多聲波傳遞的步驟，能在嘈雜的環境中實現清晰的聲音還原，而且聲波也不會因為在空氣中擴散而影響到他人。

骨傳導技術分為骨傳導揚聲器技術和骨傳導麥克風技術：

1. 骨傳導揚聲器技術 用於受話，受話即聽取聲音。氣導揚聲器是把電信號轉化為的聲波（振動信號傳至聽神經。而骨傳導揚聲器則是電信號轉化的聲波（振動信號）直接通過骨頭傳至聽神經。聲波（振動信號）的傳遞介質不同。
2. 骨傳導麥克風技術 用於送話，送話即收集聲音。氣導送話是聲波通過空氣傳至麥克風，而骨傳導送話則直接通過骨頭傳遞。

利用這些骨傳導技術製造的耳機，稱之為骨傳導耳機，也被稱作骨導耳機、骨感耳機、骨傳耳機和骨傳感耳機。