Sound Sensor: Advantages and Disadvantages

This page explores the pros and cons of sound sensors.

Definition: A sound sensor converts air pressure variations (sound) into electrical current.

These sensors are dynamic, using an induction coil placed in the magnetic field (H) of a permanent magnet attached to a diaphragm. Sound sensors are commonly known as microphones.

Types of Sound Sensors:

• Dynamic Microphone (Uses Electromagnetic Induction)
• Carbon Microphone
• Ribbon Microphone
• Condenser Microphone (Uses capacitance change)
• Piezoelectric microphone (Uses piezoelectricity)

Sound sensors are typically connected to a pre-amplifier before the sound is recorded, transmitted, or played through a loudspeaker. They are used in homes, offices, and outdoor applications. Figure 1 (above) shows a dynamic microphone.

For more information, refer to Microphone basics and types and Microphone vs Loudspeaker.

Advantages of Sound Sensors

• Security Systems: Sound sensors are often used in security systems.
• Speech Recognition: They work with speech recognition software to convert speech to text, which is faster than typing and helpful for people with disabilities.
• Real-time Manipulation: Sound can be easily manipulated in real time, eliminating the need for pre-recording.
• Voice Activation: Sound sensors enable voice activation systems in cars, improving safety by allowing drivers to control functions like the radio hands-free.
• Affordability: Sound sensors are generally affordable.
• Wireless Freedom: Wireless sound sensors provide freedom of movement and eliminate the need for cabling.

Disadvantages of Sound Sensors

• Large File Sizes: Sound files require significant memory space.
• Inaccurate Voice Recognition: Voice recognition software is less accurate than manual typing. It can be difficult to distinguish between similar-sounding words (e.g., “there” and “their”).
• Interference: Sound sensors can pick up nearby radio signals, requiring interference cancellation microphones, which increase the cost.
• Limited Range: Wireless microphones have a limited coverage range.
• Limited Battery Life: Wireless microphones have shorter operation times due to battery life compared to condenser microphones.
• Hardware Requirements: Sound sensors often need to be mounted on cards for specific applications, increasing hardware usage.