Old alarm clocks and many doorbells and telephones emit a signal due to the blows of “hammer” metal hemisphere of the bell.
If you are annoying it’s pretty sharp rattling, stick a bell in place of hitting it square of adhesive tape or medical adhesive tape device will beep “whisper”.
.
Recommend to read
WILL WARM AND COOK THE BIOGAS
Biogas. Used in Ancient China, and then millennia later, once again "open" as "non-traditional, environmentally friendly energy source of the XXI century", it attracts a growing attention...
A-129 MANGUSTA
In Italy, the design and manufacture of helicopters is concentrated mainly in the company Agusta (Construzione Aeronautiche Giovanni Agusta SpA), located in Gallart in the North of the...