ASHA is the national professional, scientific, and credentialing association for 228,000 members and affiliates who are audiologists; speech-language pathologists (SLPs); speech, language, and hearing scientists; audiology and speech-language pathology assistants; and students. Audiologists specialize in preventing and assessing hearing and balance disorders as well as providing audiologic treatment, including hearing aids. SLPs identify, assess, and treat speech, language, and swallowing disorders.