Modulaatiota

Modulaatio, or modulation, is a term used in Finnish to describe the process of altering a property of a signal or system to convey information or to change its state. In telecommunications and signal processing, modulation encodes information by varying a carrier signal. Analog modulation includes amplitude modulation (AM), frequency modulation (FM) and phase modulation (PM), where respectively the amplitude, frequency or phase of the carrier is changed. Digital modulation uses discrete signal levels, examples include ASK, FSK, PSK and QAM; modern systems often combine these with multiple subcarriers as in OFDM. The choice of modulation method reflects trade-offs between bandwidth, power efficiency, noise tolerance and implementation complexity. Applications include radio broadcasting, television, data communications and mobile networks.

In music theory, modulation means changing the tonal center or key during a piece. This can be done diatonically through pivot chords, or by more abrupt chromatic or common-tone techniques. Typical goals include contrast, development or a shift in emotional character. Common examples are modulations by a perfect fifth or a shift between relative major and minor keys. Modulation adds structure and variety to a composition and is a fundamental tool in tonal harmony.

In Finnish usage, modulaatio covers both senses—signal processing and music theory—and the intended meaning is usually clear from context. The term is widely used in technical writing as well as in music literature.