Ultrasonic means "at a sound pitch too high for human ears". A young person can hear up to roughly 20,000 vibrations a second; anything faster than that is ultrasonic.

Ultrasonic超音波的(ultrasonic) means "at a sound pitch too high for human ears"意思是「音高高到人耳聽不見」 A young person can hear up to roughly 20,000 vibrations a second一個年輕人大概可以聽到每秒兩萬次震動 anything faster than that is ultrasonic比這更快的就是ultrasonic

The key idea to hold on to is that ultrasonic sound is still real sound — it moves through air and water and bodies just like the sound you hear. Only your ear fails; the sound does not stop existing.

The key idea to hold on to is要記住的重點是 that ultrasonic sound is still real soundultrasonic sound仍然是真正的聲音 it moves through air and water and bodies just like the sound you hear它會像你聽得到的聲音一樣，穿過空氣、水，還有身體 Only your ear fails只是你的耳朵失靈了 the sound does not stop existing聲音本身並沒有因此消失

That is why animals matter here: dogs, bats, mice and dolphins hear well above our limit, so a "silent" dog whistle is silent only to you. And it is why the word turns up in so many machines.

That is why animals matter here這就是為什麼動物在這裡很重要 dogs, bats, mice and dolphins hear well above our limit狗、蝙蝠、老鼠和海豚聽得到的範圍遠超過我們的極限 so a "silent" dog whistle is silent only to you所以一個「無聲」的狗哨，只對你來說是無聲的 And it is why the word turns up in so many machines而這也是為什麼這個字會出現在這麼多機器裡

Ultrasonic waves bounce off things and come back, so we use them to see inside the body (that is the same technology as a pregnancy scan), to measure distance in a car's parking sensors, and to clean glasses and jewellery in a little tank, where the fast vibrations shake the dirt loose.

Ultrasonic waves bounce off things and come backUltrasonic waves（超音波）會撞到東西再反彈回來 so we use them to see inside the body所以我們用它們來看身體裡面 (that is the same technology as a pregnancy scan)（跟做孕婦超音波檢查是同一種技術） to measure distance in a car's parking sensors用來量車子停車感應器的距離 and to clean glasses and jewellery in a little tank還有在一個小水槽裡清洗眼鏡和珠寶 where the fast vibrations shake the dirt loose那裡快速的震動會把髒污震鬆

It is an adjective, used before a noun: ultrasonic waves, an ultrasonic sensor, ultrasonic cleaning. There is an adverb, ultrasonically, but it is rare and technical.

It is an adjective, used before a noun它是形容詞，用在名詞前面 ultrasonic wavesultrasonic waves（超音波） an ultrasonic sensoran ultrasonic sensor（超音波感應器） ultrasonic cleaningultrasonic cleaning（超音波清洗） There is an adverb, ultrasonically也有副詞ultrasonically but it is rare and technical不過很少見，而且很專業