1. Earbuds
    Pros:
    - cheap,
    - easily found (there may be a couple under your bed right now)

    Cons:
    - hurt like hell inside a helmet
    - can easily fall ‘out of place
    - annoying and distracting

  2. Stereo system
    Pros:
    - high volume output
    - nothing in your helmet

    Cons:
    - cumbersome to install
    - poor battery-life

  3. Helmets with built-in speakers
    Pros:
    - comfortable to wear
    - loud and clear

    Cons:
    - very expensive
    - solution cannot be transferred to another

  4. Helmet speakers, wired & in-padding (e.g. Sena, Cardo, Outdoor Tech Chips)
    Pros:
    - more comfortable than earbuds
    - lightweight

    Cons:
    - sound can be ‘tinny’
    - battery life
    - can hurt ears if placed too close
  5. Helmet transducers, wireless & externally mounted (e.g. Domio, Headwave)
    Pros:
    - most comfortable choice
    - nothing in your ears or helmet padding
    - easy to install
    - can be used on multiple helmets
    Cons:
    - expensive
    - performance varies from helmet to helmet