A signal modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the instantaneous amplitude of the wave is varied in proportion to that of the message signal, such as an audio signal. This technique contrasts with angle modulation, in which either the frequency of the carrier wave is varied, as in frequency modulation, or its phase, as in phase modulation. Amplitude modulation was the earliest modulation method used for transmitting audio in radio broadcasting. It was developed during the first quarter of the 20th century, beginning with Roberto Landell de Moura and Reginald Fessenden's radiotelephone experiments in 1900. This original form of amplitude modulation is sometimes called double-sideband amplitude modulation (DSBAM), because the standard method produces sidebands on either side of the carrier frequency.
How AM Works
A method of transmitting radio signals by varying the carrier wave's amplitude, or strength, according to the input audio or data signal. The amplitude of the carrier wave is modulated by the signal being transmitted, creating a wave whose amplitude varies with the signal.
- Transmission: AM radio signals travel as ground waves and skywaves, making them particularly effective for airing programming and advertisements at great ranges, especially at night when atmospheric conditions allow signals to skip across vast areas.
- Coverage: AM radio signals can reach broad audiences over long distances, often even beyond state or national borders.
Advantages for Advertisers
AM radio offers cost-effective advertising opportunities and can be highly targeted to specific regional markets. Advertisers leverage these broadcasts to connect with loyal listener bases who tune in for talk shows, sports commentary, news updates, and other spoken-word content.
- Local Reach: Local businesses often find AM spots an accessible and budget-friendly entry point into broadcast advertising, allowing them to reinforce brand awareness and engage with potential customers who trust long-established local radio personalities.
- National Campaigns: AM’s broad coverage area supports national and regional campaigns, enabling marketers to reach a wide demographic spread at relatively low production and placement costs.
Marketing Applications
In a world where digital channels vie for consumer attention, AM radio’s distinctive voice-focused programming and its heritage as a familiar, community-based platform still make it a valuable channel for sales-driven marketing efforts. AM radio remains a vital medium for reaching niche audiences and local communities.
Additional Acronyms for AM
- AM - Account Manager