"Je vous mets sur haut-parleur."

Translation: I am putting you on speaker.

[deactivated user]

Why not loud speaker?

[JBOXY]

Why not le haut-parleur?

[jchildress14]

I agree with both of these questions. In English, it would be either "on the loud speaker" or "on speakerphone." I've never heard "on speaker."

Why isn't there an option to report that the English sentence is incorrect?

[CJ.Dennis]

For me, "loud speaker" implies a PA system. "I'm putting you on speaker" is a very common, if somewhat idiomatic expression in Australia.

There is an option to report a problem with the sentence. Click the flag icon and there will be one or two options. One is "My sentence is right", the other is "There's something wrong with this sentence", where you have to explain yourself.

[de_ore_leonis]

"On speaker" is also common in the US.

[Lyrobo]

I'm British and my family use it all the time.

[TheHandShand]

Agreed. Loud speaker to me, a musician, is a PA (public address) system.

And saying to someone during a call, "I'm putting you on speaker." Or "you're on speaker" is an extremely common shortform to saying "speakerphone".

[mayenneminuit]

This was a tough one to try and figure out

[Simon_Bell]

The pronunciation of the female voice is atrocious. I wish Duolingo would sort it out. Reported. Again.