MSMA (monosodium methanearsonate) is an arsenic-based grass killer. It kills grassy weeds such as crabgrass and goosegrass without harming most turfgrasses. It contains organic arsenic that, according to the University of Tennessee Extension, is less harmful than aspirin.
There are several styles of hearing aids available, from the smallest - Invisible in the Canal (IIC) to the largest and strongest - Power Behind the Ear (BTE), and the very popular Receiver in the Canal (RIC) - made to fit most hearing losses while remaining nearly unseen.
Behind the ear (BTE) hearing aids. BTE aids have an earmould that fits snugly inside your ear, while the rest of the aid rests behind your ear. Some models have twin microphones, which let you switch between all-round sound and a more directional setting that helps you focus on what you want to hear in noisy places.