K. Skill-based questions.
1. How can extra loud sounds cause permanent
hearing loss?
2. Why can humans not listen to very low
frequency vibrations?
3. How do ultrasound vibrations help in cleaning
dishes?
Answers
Answer:
1) Loud noise can damage cells and membranes in the cochlea. Listening to loud noise for a long time can overwork hair cells in the ear, which can cause these cells to die. The hearing loss progresses as long as the exposure continues. Harmful effects might continue even after noise exposure has stopped.
2) Humans cannot hear less frequency than 20Hz and more than 20,000Hz. ... ⭕Sound below 20Hz is called infrasound and above 20,000Hz is called ultrasound. ⭕We have small ears because of that our pinna cannot take much sound at a time. That is why we are not able to listen frequency low than 20Hz.
3) Ultrasonic cleaning uses cavitation bubbles induced by high frequency pressure (sound) waves to agitate a liquid. The agitation produces high forces on contaminants adhering to substrates like metals, plastics, glass, rubber, and ceramics. This action also penetrates blind holes, cracks, and recesses.