| instrument(noun, technology, device, machine, gadget) |
| invention(noun, technology, device, machine, gadget) |
| machine(noun, technology, device, gadget) |
| mechanism(noun, technology, device, machine, gadget) |
| tool(noun, technology, device, machine, gadget) |
| utensil(noun, technology, device, machine, gadget) |
| audio(noun, technology, device, radio, computer) |
| listening(noun, technology, device, radio, computer) |
| noise(noun, study, sound, science, audio) |
| sound quality(expression, sound, audio, acoustics) |
| audio system(expression, technology, music, audio, listening) |
| echo(noun, study, sound, science, audio) |
| music listening(expression, technology, music, audio, listening) |
| sound transmission(expression, sound, audio, acoustics) |
| stereo(noun, technology, device, radio, computer) |
| stereo system(expression, technology, music, audio, listening) |
| audibility(noun, study, sound, science, audio) |
| balanced armature(expression, technology, acoustics, headphone) |
| electret(noun, technology, acoustics, headphone) |
| electroacoustic transducers(expression, technology, music, audio, listening) |