Electronic instruments are defined as instruments that:

The definition of electronic instruments focuses on their method of sound production. Electronic instruments are designed to produce and amplify sound using electronic means like oscillators, amplifiers, and digital sound processing. This technology allows for a wide range of sounds and capabilities not possible with traditional acoustic instruments.

For instance, synthesizers generate sound electronically rather than relying on physical vibrations from strings or air. Similarly, electric guitars use pickups to convert string vibrations into electrical signals, which are then amplified. This electronic manipulation of sound distinguishes them from purely acoustic instruments that depend solely on physical sound production methods.

Other choices suggest characteristics that do not apply to all electronic instruments. For example, the suggestion that instruments are always made of wood is inaccurate, as many electronic instruments incorporate plastic, metal, and other materials. The idea that they produce sound only through acoustics ignores the fundamental principle of electronic sound generation. Lastly, while many electronic instruments can be played manually, some can also be operated through automated systems or sequencers, making manual playing a non-essential characteristic. Thus, the correct definition correctly captures the essence of electronic instruments.