The global hearing aid market was valued at over $10 billion in 2021. Critics argue that the five largest manufacturers, who control more than 90% of the market, have kept prices high. But a recent ruling by the Food and Drug Administration allowing for the sale of over-the-counter hearing aids could improve access for millions. The new devices, for adults with mild to moderate hearing loss, cost as little as $199 and can be purchased at retailers like Best Buy, CVS and Walmart.