Every year television stations receive hundreds of complaints about

the loudness of advertisements. However, federal rules forbid the

practice of making ads loud than the programming. In addition, 【M1】__________

television stations always operate at the highest sound level allowing for 【M2】__________

reasons of efficiency. According to one NBC executive, no difference

exists in the peak sound level of ads and programming. Given this

information, why do commercials sound so loud?

The sensation of sound involves variety of factors in addition to its 【M3】__________

peak level. Advertisers are skilful at create the impression of loudness 【M4】__________

through their expert use of such factors. One major contributor of the 【M5】__________

perceived loudness of commercials is that much less variation in sound

level occur during a commercial. In regular programming the intensity of 【M6】__________

sound varies over a large range. However, sound levels in commercials

tend to stay at or near peak levels.

Another “tricks of the trade” are also used. Because low-frequency 【M7】__________

sounds can mask higher-frequency sounds, advertisers filter out any

noises in that may drown out the primary message. In addition, the 【M8】__________

human voice has more auditory impact in the middle-frequency ranges.

Advertisers electronically vary voice sounds so that they stay within such

a frequency band. Another approach is to write the script in which lots

of consonants are used, because people are most aware of consonants 【M9】__________

than vowel sounds. Finally, advertisers try to begin commercials with

sounds that are highly different from that of the programming within 【M10】_________

which the commercial is buried. Because people become adapted to the

type of sounds coming from programming, a dramatic change in sound

quality draws viewers’ attention. For example, notice how many

commercials begin with a cheerful song of some type.

【M6】