|As long as the firmware update is the official one provided by the manufacturer for that make & model, and you carry out the update exactly as per their instructions, your headphones will not be damaged.|
However, you may first want to read the notes which tell you what the firmware update actually does (ie what it fixes or what new features it adds). You may decide that you don't need it. It's not compulsory to update it, it's your decision.
message edited by phil22