Hi Vicky

It is possible to change the language of most of the content in Totara through Site admin > Language >Language customisation 

When I did a search I found the string memberofcohort with the text Member of audience '($a)'. - if you takeout the place holder   '($a) then the audience name shouldn't show. This will hide this information for everyone which may not be what you want.

Alternatively you could rename the audiences with their Audience ID and add details of the Audience in the Description field for the Audience.

Regards