Toppers Study Toppers Study Toppers StudyGet CBSE Notes for Class 9 Science – 12. Sound: The Types of Sound. Clear, exam-focused notes with key concepts, formulas & solved examples.
CBSE Notes for Class 9 Science chapter 12. Sound: The Types of Sound, quick revision notes for Class 9 Science chapter 12. Sound The Types of Sound, Chapter-wise CBSE Revision Notes, CBSE Notes PDF Free Download, CBSE One Liner Notes Class 9, Half Yearly Revision Notes, CBSE Revision Notes Class 9 Science
Get CBSE Notes for Class 9 Science Chapter 12. Sound: The Types of Sound prepared by experts as per the latest NCERT syllabus and CBSE exam pattern. These concise and easy-to-understand notes cover important definitions, formulas, diagrams, and key concepts from the chapter to help students in quick revision and effective exam preparation. Whether you are studying for school tests, board exams, or competitive exams, these notes provide a reliable study resource. Designed in simple language with point-wise explanations, they save time and enhance learning efficiency. Download free PDF notes, explore solved examples, and strengthen your understanding of [Topic Name] for scoring high marks. Perfect for Class 9 students who want clear, structured, and exam-oriented notes for CBSE Science.
The Types of Sound :
We can't hear all kinds of sound. On the basis of hearing there are three types of sound:
(1) Infrasound : The sound of frequency less than 20 Hz is called infrasound or infrasonic sound. Such type of sound can't be heared by human being. There are some animals that produce infrasound.
(i) Rhinoceroses : Rhinoceroses communicate using infrasound of frequency as low as 5 Hz.
(ii) Whales and Elephant : Whales and elephants produce sound in the
infrasound range.
(iii) Rats and snake : It is observed that some animals get disturbed before earthquakes. Earthquakes produce low-frequency infrasound before the main shock waves begin which possibly alert the animals.
(2) Audible sound : The sound of frequency between 20 Hz to 20000 Hz is called audible sound.
(3) Ultrasound : Frequencies higher than 20 kHz are called ultrasonic sound or ultrasound. Ultrasound is produced by dolphins, bats and porpoises. Rats also play games by producing ultrasound.
Hearing Aid: People with hearing loss may need a hearing aid. A hearing aid is an electronic, battery operated device. The hearing aid receives sound through a microphone. The microphone converts the sound waves to electrical signals. These electrical signals are amplified by an amplifier. The amplified electrical signals are given to a speaker of the hearing aid. The speaker converts the amplified electrical signal to sound and sends to the ear for clear hearing.
Ultrasounds are high frequency waves. Ultrasounds are able to travel along welldefined paths even in the presence of obstacles.
Ultrasounds are used extensively in industries and for medical purposes.
Applications of Ultrasound:
(i) Ultrasound is generally used to clean parts located in hard-to-reach places, for example, spiral tube, odd shaped parts, electronic components etc.
(ii) Ultrasounds can be used to detect cracks and flaws in metal blocks.
(iii) Ultrasound is used in the medical field to detect illnesses/diseases.
(iv) Ultrasound is used in a device named SONAR, which is used to measure the depth of ocean in the ships.
For students preparing for board exams or competitive assessments, CBSE notes have become an indispensable tool. These notes summarize the NCERT textbooks, highlighting key concepts, formulas, definitions, and diagrams in a concise and easy-to-understand format. Unlike lengthy textbooks, CBSE notes allow students to focus on the most important points, saving valuable time during revision.
In conclusion, CBSE notes are not just a revision tool—they are a strategy. When used correctly, they help students cover the syllabus efficiently, improve retention, and approach exams with confidence. For exam-going students, the combination of structured notes, practice, and consistent revision is the key to achieving top results.
Ace your exams with CBSE Notes for Class 9 Science chapter 12. Sound: The Types of Sound. These notes provide a clear explanation of important concepts, formulas, diagrams, and solved examples from the NCERT syllabus. Specially designed for Class 9 students, the notes are structured in a simple, point-wise manner to make revision quick and effective. Whether you are preparing for school tests, board exams, or competitive exams, these Science notes will boost your confidence and save valuable study time. You can also download Science class 9 chapter 12. Sound free PDF notes for offline learning. With easy-to-grasp language, exam tips, and well-organized content, these CBSE Science notes on chapter 12. Sound – The Types of Sound are the perfect study companion for scoring high marks and mastering the subject.
CBSE class 10 Science notes are available completely free in PDF, and these all notes are quick revising materials that help you prepare for your upcoming board exams. Students can easily access CBSE notes pdf free download class 10 Science and get free CBSE notes class 10 Science notes designed strictly as per the latest NCERT syllabus. These Class 10 CBSE notes and Class 10 Science notes are short, simple, and to the point, making them perfect for last-minute revisions. You can also refer to NCERT book notes for class 10 that cover every chapter in an easy-to-understand manner. With these Quick revision notes Science class 10, you save time while covering all important formulas, definitions, and concepts.
Download worksheets and assignments for better practice and revision.