Overview of Audio Surveillance Tools
Audio surveillance equipment is used by intelligence agencies, law enforcement, and private investigators to monitor and record subjects in various settings. Audio surveillance can be conducted from a distance using covert listening devices hidden inside the dwelling. Or, audio amplifiers can be attached to a person inside the house (such as an informant). Also, audio amplifiers can be used to amplify sounds from a distance.
This article will review audio amplification systems and digital audio recording devices. In addition, I’ll suggest where you can purchase the equipment at Amazon.com and the Home Security Superstore.
Audio Amplifier Systems
Audio amplifiers are electronic devices that amplify low-power audio signals (primarily composed of frequencies between 20 – 20 000 Hz, the human range of hearing) to a higher level. The amplification equipment can be used either indoors or outdoors to listen to sounds and conversations at a distance.
Audio amplification equipment helps private investigators and police officers to hear conversations that are taking place in a nearby location, such as in another room or on the other side of the park.
This lets private investigators listen to what is being said without the other party’s knowledge. The basic point is to hear what is being discussed while remaining unseen. Also, investigators use audio amplification systems for many other purposes. For example, eavesdropping on conversations from a distance. Or to check in on a witness.
The amplification devices can be targeted by pointing the unit in the direction of the sounds you are interested in hearing. The target could be a person having a conversation with someone else, someone talking on the phone, or multiple individuals having a group discussion. The sounds that are targeted are then amplified as much as ten times.
The typical equipment with the sound amplification tool includes the listening device, the “sound catching” cone, a microphone, mounting clips, batteries, carrying, and storage cases. In addition, some packages include an audio out jack and cables to record conversations. Also, many packages include noise reduction and wind reduction capabilities to help filter out unwanted background noise. This can be helpful when playing back the recording.
Other Uses for Sound Amplification Equipment
In addition to surveillance, audio amplifiers can also be used for nature observation, concerts, hunting, bird watching, listening to lectures, personal security, sporting events, or watching TV. The listening distance will vary depending on the particular device you are using, but count on being able to pick up conversations from over 300 yards away.
As a protection mechanism, some audio amplifiers come equipped with auto-shutoff in case the sound becomes too loud.
Digital Voice Audio Recorders
Digital audio voice recorders are devices that record sounds in a digital format, most often used to record voices. The sound files are stored on the device and played back either directly on the device or copied to a computer.
For many purposes, the equipment can be used by almost anyone, including students, attorneys, law enforcement, and even private investigators. Private investigators can use digital audio voice recorders to record case notes, record witness interviews, and capture voices and sounds as needed during a surveillance mission.
When working as a private eye, you don’t always have the time to stop and write everything down. In old movies and TV shows, P.I.’s often pulled out a handheld flip pad to jot down a few notes or facts when working on a case. However, modern detectives are always on the go, and their hands aren’t always free for writing.
For example, you may be on a long surveillance mission. Your hands may be busy working with audio equipment, taking pictures with cameras, or driving a vehicle to follow a subject.
A voice recording device will help you capture important notes and set reminders without missing a step while keeping your hands free to perform other tasks. Then, when you return to your office, replay the notes and transcribe what is meaningful to your PC, tablet, or phone.
Voice recorders are great when you don’t have a pen and need to record important information. Use a recorder to capture ideas and thoughts on your case, record surveillance notes, or set important reminders.
Many of the latest models offer high-quality sound, slim designs for easy storage and concealment, one-touch recording, and plenty of storage space to keep hours of data. Additional equipment for connecting to a computer or mobile device is often included.
Sony Digital Voice Recorder
I recommend this equipment for every private investigator, especially those conducting surveillance and interviewing witnesses.
The recording device has an amazing 57 hours of battery life, so you can spend more time using the recording and less time charging. In addition, it comes with a handy built-in direct USB connection at the bottom to allow you to quickly and easily transfer audio files to your computer or tablet.
You can use it to record witness statements, interview conversations, and record your own case notes. Also, it is small enough to fit secretly in your pocket to record conversations covertly.
Important Note: Check your state and local laws about recording witnesses or other spoken statements. It is illegal in most states to record a person’s voice without their consent.
Legal Considerations for Audio Amplifiers and Audio Surveillance Equipment
Please note that these tools are not specifically designed to intercept oral communication surreptitiously. Use for this purpose seriously violates federal laws. Check your state and local laws before purchasing such equipment, and be aware of those laws when using the tools.
The information contained in this article is not intended to condone any unauthorized use of audio amplifiers, such as illegal tapping into other people’s phone conversations. It is the purchaser’s responsibility to comply with all Federal & State privacy rules & regulations.
If you have any questions about audio amplifiers and sound surveillance equipment, please leave a comment below. Or, learn about other types of spy gear and equipment.
Related: How to find hidden surveillance bugs.
What are the popular brands of audio amplifier and surveillance systems and where I purchase them from?