The Professor provides updates on some recent products and retests the sound level of the alp Propane Generator. Use code ...

You may have observed that older people have more difficulty following a conversation in a noisy environment. Most people attribute this problem to being deaf. However, many of these people are not ...

Secondly, while the aircraft is taking off and landing, noise levels measured 100 m (330 ft) from the vertipad stayed below 65 dBA over more than 20 VTOL tests, with the aircraft rising to or ...