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.
hearing aid an instrument to amplify sounds for those with hearing loss. There are two types of electronic hearing aids: the air-conduction type, which is worn in the external acoustic meatus, and the bone-conduction type, which is worn in back of the ear over the mastoid process.