The Buddha means Oneness. When everything is Oneness, there is nothing but Oneness, the Buddha. Then, there can be no other sound but the voice of the Buddha. So, the voice of the Buddha has no beginning and no end and includes not only all sounds but also silence. No one can stop it reaching our ears even for a moment. Furthermore, all the sounds you make in your daily life are also the sounds of the Buddha because you are also part of the Buddha.
The key problem is that we don’t recognise it while seeing and hearing it. In order to recognise the sound of the Buddha, you should know that there is no difference at all between any two things: silence and sound, air and a tree, tea and a cup, and so on. Hearing everything as the same is hearing everything as it is, which is to hear the voice of the Buddha. Seeing everything as the same is seeing everything as it is, which is to see the Buddha.
All writing ©Boo Ahm. All images ©Simon Hathaway