What are Sound Transducers
- The sound transducer is an instrument that used for the transformation of the sound into the electrical signal and electrical signal into the sound.
- The acoustic waves are defined as the sound that we hear. The frequency range of the sound is from one hertz to several hundred hertz, but the range for the sound that we can hear is twenty to twenty thousand hertz.
- There are the 2 main categories of the sound transducers first one is input transducers and the second one is output transducers.
- Input transducers are that converts sound energy into the electrical energy, an example of these transducers is a microphone that converts our sound into an electrical signal and sends to the loudspeaker.
- The output transducers are that changes the electrical signal into the sound wave, its example is loudspeaker that converts the electrical signal into the sound received by the microphone.
- These transducers have the ability to transform less and higher frequency sound waves lesser frequency waves are known as infrasound wave and larger frequency sound waves are recognised as the ultrasound.
What is Sound
- Sound is the type of energy generated by the vibration produced by beating drum, vibrating tuning fork and the vibration's energy depends on the source that producing these vibrations.
- The frequency of the sound oscillations produced by the drum is less while sound producing from the cymbal (it is a musical device) has larger frequency.
- Like an electrical signal, the sound wave also has velocity, frequency and wavelength.
- The wavelength (λ), frequency (f) of the sound rely on the source that produced the waves. But the velocity of the sound depends on the propagation matters like solid, liquid, or gases.
- The mathematical relationship among the frequency, velocity and wavelength is written here.
- The wavelength (λ) can be defined as the time required for completion of the one sine waveform.
- Frequency (f) is the no of sine waveform in one second, its unit is hertz.
- Velocity (v) is the distance covered by the wave in one second, its unit is m/s-1
Input Sound Transducer
- The microphone is defined as the input sound transducer because it converts the electrical energy into the sound.
- There are various categories of the mic according to the electric transducers that are working with it.
- Mic also consists of the sound filters circuitries and repeaters circuits that maintain the signal strength after some time.
- The features of the mic are electric and acoustics. The sensitivity of the mice can be defined as the millivolts of the electrical signal produced by the per-unit intensity of the acoustic waves.
- The impedance value of the mic defined the value of the electrical signal at the output if the impedance is larger than the output will also large, impedance is less output will also less.
- Now we discuss the carbon microphone and its working.
- The mic was invented in the world that used in old fashion telephones for conversation is was carbon mic.
- Nowadays these mics have been substituted with the electret mics.
- Carbon mics consist of the piece of the carbon among the diaphragm and back-plate.
- When the pressure is an external sound signal is applied to the carbon piece, then the value of the resistance decreases.
- The sound waves collided with diaphragm cause to decrease the resistance of the carbon piece.
- The output delivered by the carbon mic is according to the sound standard.
- The given below diagram explains the structure of the carbon mic.
Output Sound Transducer
- The use of mic is useless if it is not connected with the output for the conversion of the electrical signal into the sound wave.
- The examples of the output transducers are speaker, bells, that converts an electrical signal into the sound.
- Ear-phones are one of the best output transducers that have used earlier than the mic.
- In previous years the ear-phones were used with Morse key (it is an electrically operated switch used in telegraph) in the transmission of the signal through telegraph.
- With the discovery of the mic, there were several models of the input and transducers were invented like the telephone.
- Speakers are exits in different physical structure, frequency limits and area. The transducers are also known as pressure modules because they convert an electrical signal into the pressure of the air.
- For high pressure, the speaker comprises a motor that converts an electric signal into the sound waves and diaphragm that pushes adequate air to make the vibrating effect hearable.
- In given below diagram the speaker internal structure is shown.
Applications of the Sound Transducers
- These are some important applications of the sound transducers that are described here, with detailed.
- Sound transducers are used in the telecommunications almost all telephone and mobiles consists of these transducers.
- Television and LCDs also consist of the sound transducers.
- Computer, laptops, radio also uses these transducers for the sound.
- In a conference or larger conventions hall, these are used for the propagation of the sound to the people.