1.  0.1apparentDoppler effectEar trumpetfrequencyHertzlaws of reflectionpitchsound navigation and rangingvibration is a hearing aid, which is useful by people who have difficulty in hearing.
2. The frequency of the sound as received by a listener is different from the original frequency produced by the source whenever there is a relative motion between the source and the listener. This is known as  0.1apparentDoppler effectEar trumpetfrequencyHertzlaws of reflectionpitchsound navigation and rangingvibration.
3. In SONAR, by measuring the change in the  0.1apparentDoppler effectEar trumpetfrequencyHertzlaws of reflectionpitchsound navigation and rangingvibration between the sent signal and received signal, the speed of marine animals and submarines can be determined.
4. The  0.1apparentDoppler effectEar trumpetfrequencyHertzlaws of reflectionpitchsound navigation and rangingvibration frequency is the frequency of the sound as heard by the listener.
5. Rapid back and forth motion of a particle about its mean position is called  0.1apparentDoppler effectEar trumpetfrequencyHertzlaws of reflectionpitchsound navigation and rangingvibration.
6.  0.1apparentDoppler effectEar trumpetfrequencyHertzlaws of reflectionpitchsound navigation and rangingvibration is a unit of frequency.
7. Reflection of sound obeys the  0.1apparentDoppler effectEar trumpetfrequencyHertzlaws of reflectionpitchsound navigation and rangingvibration.
8. The abbreviation SONAR is  0.1apparentDoppler effectEar trumpetfrequencyHertzlaws of reflectionpitchsound navigation and rangingvibration.
9. The whistle of a fast moving train appears to increase in  0.1apparentDoppler effectEar trumpetfrequencyHertzlaws of reflectionpitchsound navigation and rangingvibration as it approaches a stationary listener.
10. The minimum time gap between the original sound and an echo must be  0.1apparentDoppler effectEar trumpetfrequencyHertzlaws of reflectionpitchsound navigation and rangingvibration second.