I found an image in the 1930's Dutch catholic magazine I'm leafing through, of a completely new Philips-speaker installation in the Al-Azhar Mosque in Cairo, Egypt. You can see a man putting up a sign in the court yard saying 'Philips Radio' and the Philips star logo.
This must have been installed ca. 1936 under the auspices of Mustafa al-Maraghi who was rector at the time.
The author of the little text clarifying the picture applauds the use of modern technology for religious services. He writes: 'In our country people are hesitant toward or reject outright the idea of speakers in a catholic church. The muslims thinks differently about the application of modern technology and have just installed a completely new speaker-system!'