Just a couple of things to take in consideration when using headphones outside (sorry for being a bore):Sorry to derail the couch to 5k, do they talk you through what you need to do while on the run? If so, Iāll need to look for some wireless headphones if I want to have a go at it.
Just be careful with the volume when your out running, its tempting to increase the volume when the background noises are loud but please be careful it might damage your hearing in the long run. Its probably better to go for noise cancelling ones, although they are a bit if a pain in the areas if you have tinitus since the silence amplifies the issues. Bose is a popular brand, not sure about their in-ears ones.
Also consider not going for Bone conduction headphones (I think thats what the dud in the reddit thread was using) when running. The guy used headphones that used vibrations to send sound to the inner ear, it did not cover his ears, so he had difficulties hearing the music so he kept increasing the volume. After a couple of weeks of extremely loud volume his tinnitus got more prominent, it was after the damage was done that he figured out what was happening.
Sorry if I am scarring you, I just don't want you to end up damaging your hearing and/ or get tinitus. I have it and its tit. I have been to specialist and apparently I have no hearing damage and my ears are fine, I am just very unlucky. It might be due stress, weight or some blockages in ear but thats not something the doctors wanted to consider since its a issue not taken seriously in Norway- as long as its not making you suicidal they are like "meh, you just have to live with it".