How do I turn on the sound / speaker on my iPad?

Although I have been into settings/sound & all the appropriate sliders seem to be turned on (& checking a calendar / reminder alert etc does produce the appropriate sound from the speaker & the volume slider is at maximum), when I use a program that should produce sound, e.g. iTunes, or a video, I am not getting any sound from my iPads speaker, not even keyboard clicks - unless I connect headphones.

This is a new iPad, & the problem has been there since day one.

Is there something else I need to turn on to get any sound out of the speaker?