One What is the shortest wavelength you can hear?

[Tuxedo]

One What is the shortest wavelength you can hear?
TwoA special device can transmit out-of-phase sound from a noisy jackhammer to earphones worn by its operator. Over the noise of the jackhammer, the operator can easily hear your voice while you are unable to hear his, Explain.

 

[pixel01]

The shortest wavelenghth you can hear is about 20-40Hz.

Probably the device has some resonant sensors, that only respond to the wavelength of human voice (the jackhammer's sounds should have lower wavelengths). The device also isolates the all the sound around and only the signals received by the sensors are amplified and led to his ears

 

[FredGarvin]

No. That's the longest wavelength.

EDIT: I took out the rest of the answer because this is obviously homework. What realtion do you know between frequency and wavelength?

 

[Tuxedo]

Sorry guys for wasting your time I solved it