To attract the customer's attention, you can gently touch their shoulder.

Some other strategies you can use to attract the attention of a Deaf or hard-of-hearing person include: ☆Waving your hand; ☆Tapping on the upper arm of the Deaf or hard-of-hearing person; ☆ If you are not close by, ask a person nearby to tap on the shoulder or upper arm of the Deaf or hard-of-hearing person. Also, it's important to know that as long as it is the shoulder or upper arm, it is culturally appropriate within Deaf culture to touch someone to gain attention. So, don't worry about being inappropriate! Source: deafConnectEd, 2019. Photo by cookie_studio from Freepik.