You cannot use any device to infringe upon a person's reasonable expectation of privacy. Thus, any place you would expect to be reasonably private, i.e. your own home or car is out of bounds. In a public place, however, a person cannot expect to have privacy.
man you going through unknown tunnel
blackberry devices
ears
taps
Some popular devices for listening to music on the go include smartphones, MP3 players, and portable music players like iPods.
If you’re all about clean, rich sound, there’s a big difference once you try proper gear. Wired setups still hit different, something like the Sennheiser HD600 with a decent DAC/amp combo is chef’s kiss. For portable listening, those fancy Astell&Kern or Sony Walkman players seriously elevate everything. And if you’re sticking to wireless, the Sony WH-1000XM5 or B&W PX8 are top picks—just make sure your phone supports high-res Bluetooth like LDAC. Game changer.
Yes you can but there are better listening devices.
if you don't get caught.
I was listening to my mom talk.
Listening devices (aka: 'bugs') are said to be vulnerable to the playing of sound or music from other sound producing devices (TV's - radio - players - etc) but I cannot assure that this is 100% correct.
Some of the best spy gear hearing devices available on the market include high-quality listening devices like parabolic microphones, covert earpieces, and audio amplifiers. These devices are designed to enhance sound quality and improve listening capabilities for surveillance and espionage purposes.
reflective listening