Modular audio headphone devices comprise a first user-wearable accessory and at least one headphone configured for releasable attachment to the first user-wearable accessory. The at least one headphone comprises a speaker. A speaker housing is coupled to the speaker and may be configured to form an acoustic cavity proximate at least a portion of the speaker. The at least one headphone may be configured to provide a first emitted sound pressure level (SPL) profile over a range of frequencies when the at least one headphone is attached to the first user-wearable accessory, and to provide a different second emitted SPL profile over the range of frequencies when the at least one headphone is not attached to the first user-wearable accessory.