If you are set a theme or topic for photography, it's often difficult to know where to begin, especially if it's a single word.

Start with the first thing that comes into your mind when you were first set that task, or when you first read about that competition. In your example, 'voices', what came to mind first? Was it an image or a scene? Can you recreate that? If you don't know what the word means, look it up in a dictionary. As you read the definition, what comes to your mind at that point?

The whole point of single-word topics like these are because the people that set the task are looking for unique interpretations. 'Voices' could be a choir, it could be political voices, as mentioned in one of the comments, it could be a record player, but these are just the most simple interpretations. What about voices from the point of view of mental health and mental care? What about the record shop HMV in Britain which stands for "His Master's Voice" and is represented by a dog at a gramophone?

Think about the word and where you've heard it said and the context you've heard it in. Think about it in the context that you would use it. Think about the emotion that comes to mind when you hear that word and try to reflect that emotion in a photo that you think portrays that word.

As a photographer and artist you have the freedom to interpret a challenge or a set word as you wish, so be creative. The judges may be looking as much for a creative interpretation in a response as they are for technical skill.

Note

I ask a lot of questions here and I don't explicitly answer your question as it stands at time of writing, but I'm trying to approach it from a more generic point of view, more in the sense of 'if given a topic, how do you go about portraying that topic?', which is probably a better fit for the site.