My simple invention, designed to keep my grandfather safe

TED TALK

audible - that can be heard clearly
To block out audible sounds, Jack uses earplugs when flying
Danielle’s soft voice was not audible in the crowd.  

stem from - to be the result of something
Most of her health problems stem from an accident she had when she was younger.
His love of the outdoors stems from his father.

to implant - to fix an idea, attitude etc. firmly in somebody's mind
As a busy student with little free time, Sylvia’s way of cramming for an exam would be to implant as much information in her brain right before the test.
The teenager did not know what to do but to implant the telephone number into her head since her cell phone had gone missing.

snugly - in a way that is comfortable 
I left the children tucked up snugly in bed.
The indigo jeans fit snugly against his lean hips and muscular thighs.

bulky - large and difficult to move or carry
The bulky package was much too large to be placed in the small mailbox.
Our bulky Christmas tree was so colossal that the top touched the top of the ceiling.