Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (11.89 USD): BG75597c
Coupon (12.73 USD): Cuponation9
Coupon (12.87 USD): TTSUMMER8
(CouponsFromChina.com tip: this code has to be applied in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BG9cc7f2, BGHB218, BG785c81, 2203ActiesNL, BGHECARE1, BG4ee866, BG14c65e, BGa39f8d, 9OFFSUMMER
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for Mini Size Inner Ear Invisible Hearing Aid.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).