First, make sure all necessary input/output cables are properly connected and not damaged in any way. Then check the mic input and make sure there isn't any dirt blocking the opening. Barring that, check the phone you're connected to, and make sure it wasn't left on mute or low volume. If none of these actions help, then try turning your phone off and on. A quick reboot can often fix issues like this.
While our headphones shouldn’t require any regular maintenance, you can use the following materials for cleaning: A dish with soap and warm water (detergent will work just fine) A soft cloth A toothbrush A small towel Wet the soft cloth in soap and water. Don't soak the cloth; instead, get it a little damp Gently wipe down the headphone pads with the damp cloth. For the more stubborn debris and residue, use a dry toothbrush to loosen it up and then wipe it down with the cloth. Afterwards, let it sit on the towel to air dry. Once it's dry, you can safely resume use.
Our headphones come with markers indicating which earcup is left and right. Make sure these are oriented properly before putting them on.