Pink Floyd + Helium: What Would the Sound Be?

[yasar1967]

If we were to inhale some Helium and speak, our vocal frequency will get higher producing high pitch and often comical tone.
It's due to the different wave travel speed in Helium gas compared to air which results a bigger frequency according to V=wave length x frequency

What if we filled a room with Helium and listened to a record of Floyd through a loudspeaker?
(Supposing you're holding your breath during the song :)

Would the sound be the same or distorted?- frequency wise.

 

[Astronuc]

I believe it is a matter of the acoustic coupling between the vibrating membrane (source) and medium. Lighter gases like H2 and He offer less resistance to the motion (vibration) of the source, while heavier gases e.g. N2/O2, CO2, Kr, Xe would offer greater resistance and hence lower frequency.

 

[Borek]

I can be wrong, but IMHO nothing will change - loudspeaker membrane motion is forced by the electromagnetic field, no reason for it to change vibration frequency, although it will most likely change the efficiency of transferring vibrations to the gas, so high frequencies may became louder.

When you speak you don't force frequency on the system, you only change tension in vocal cords, and the output frequency is a function of acoustic coupling Astronuc mentioned.

Then there can be problem on the other end, with your ear characteristic, no idea if it will be changed by the gas change.