Learning sign language brings a number of benefits. Here are some top reasons for learning it!
Bilingualism of any languages (whether signed or spoken) is a great booster for brains. It enriches and enhances your cognitive processes: higher abstract and creative thinking, better problem-solving, greater cognitive flexibility, better listening skills, greater academic achievement, and more! It also promotes cultural awareness, literacy, and other intellectual benefits.
Not just bilingualism, but also why not bimodalism too? Bimodal, that is using visual-spatial medium, expands your visual-perceptual skills: spatial awareness, mental rotation skill, visual sensitivity, and more!
People simply find it fascinating, beautiful, unique, graceful and/or expressive. The more signers learn ASL, the harder, the more complex, and the more challenging it gets they realize. But, in the end, it's all worth it and it's a fulfilling experience.
Fingerspelling is exactly not a language per se. It is a set of the alphabetical letters corresponding to spoken words. But, I will mention it nevertheless. After all, it's visual.
Fingerspelling helps students learn how to spell a word letter by letter. Some teachers (and students) use fingerspelling in spelling lessons in class. Receptive skill exercise is also a bonus.
American Sign Language (ASL) is (formerly the 4th in 2009) now the 3rd most studied modern/foreign language at colleges and universities in the U.S., according to the Modern Language Association's statistics (2016) after Spanish and French. In addition, it has a higher percent of enrollments above the top three.
Among hundreds of signed languages around the world, ASL is used in the U.S. and Canada. According to the 2016 Canada Census, there are 27,510 ASL (11,465) and LSQ (2,570) speakers in Canada who responded in the survey. Not everyone responded to the census. The US Census bureau doesn't list ASL in its census so it's difficult to determine a number. A common estimate in literature is up to 500,000 (sometimes up to 2,000,000) ASL speakers in the U.S.
Speech is not a language. Speech and signing are a medium or modality, while Enligsh, ASL, and other spoken and signed languages are language. Because, language is brain-based, not modality-based.
It's extremely crucial that deaf babies are exposed to a natural language (e.g. ASL, Auslan, or another signed language) within the first two years of life ("two year window").
Ear is to hearing baby as eye is to deaf baby that both equally can access to their own languages from birth, both acquire their own languages equally on the same milestones, and develop literacy skills via different means (by eye or by ear). Eventually, deaf toddlers can learn a second language -- e.g. English -- at ease.
By the way, 'baby sign language' is a cultural appropriation. It is a distorted concept as much as 'baby speech language.' Parentese exists in both signing and speech when talking with babies.
Do you think Deaf people miss out on music? Not really. What hearing people miss out is literary arts in sign language for its linguistically creative language play, poetry, and storytelling.
Visual-spatial language with its rich capabilities of cinematic devices, rhymes, rhythms, calligraphic movements, and many others adds a dynamic spice to language arts.
Human interest in communication with animals (and possibly vice versa) has been around for a long time, via speaking, signing, and/or even painting.
Using sign language with chimpanzee Chimpsky and gorilla Koko in scientific studies is one example. And speech language with parrots is another.
Basic knowledge of a signed language can be an useful communication for firefigthers, police officers and other professional civic servants, as well as scuba divers, stock traders, and more.
Naturally, cultural awareness and language competency is a must when working with Deaf and Hard of Hearing people in any settings.
You can talk conveniently in sign language with your mouth full or talk through windows of a building from a distance.
You can also talk (in signing) lively in loud discos or whisper (yes, in signing) in a church or a library.
You can be sure that nobody can "overheye" you through a door (for a window, that's a different story). Or, you even can have a private talk in public where nobody knows sign language (or maybe not, at your own risk).