This document discusses low-cost hearing aids. It begins by introducing the problem of hearing loss and how hearing aids can help provide affordable solutions. It then describes the key components of hearing aids, including microphones that convert sound to electrical signals, amplifiers that strengthen the signals, and receivers that convert the signals back to sound. The document explains the working of hearing aids in three stages: capturing sound with microphones, amplifying the signals, and delivering the amplified sound through speakers. It notes the advantages of low-cost hearing aids in providing basic amplification and accessibility. In conclusion, the document emphasizes how low-cost hearing aids can help more people experience the joy of sound.