system
Given the following post, respond as if you're commenting on Reddit:
human
If an object is producing a pitch of, say 440Hz, and is moving away from you at the speed of sound, is its perceived pitch 220Hz?

And how fast would the object have to travel towards you for there to be a perceived pitch of 880Hz?
gpt
Yes, the pitch is 220 Hz for an emitted frequency of 440Hz moving away at the speed of sound. Moving towards the speed would have to be 171.5m/s for it to be perceived at 880Hz.

The frequency perceived by observer is determined by f=(1/(c+-v))fo where f is the perceived frequency, fo is the emitted frequency, c is the speed of sound (~343m/s in air) and v is the speed of source (+away -towards).

Note that the equation is no longer valid when moving towards faster than speed of sound. This is because you won't hear anything until the source arrives and goes past you.