Listen to this: The world of earbuds is about to be transformed by startups whose products let you customize what you hear. Instead of earbuds, which typically deliver music and voice sounds through a wire, and hearing aids, which boost certain frequencies (lost to the elderly who listened to loud music through earbuds in their misspent youths), the new hearables -- wearable devices that live in your ears -- enable the customization of environmental sound. You can cherry-pick which noises you want to hear better, and which you want silenced.
