For the purpose of this chapter, the following words and phrases are defined as follows:
(a) “dBA” means the abbreviation for the sound level in decibels determined by the A-weighting network of a sound level meter or by calculation from octave band or one-third (1/3) octave band data.
(b) “Daytime hours” means 7:00 a.m. to 10:00 p.m., local time.
(c) “Department” means the department of planning and community development and or the police department.
(d) “Nighttime hours” means 10:00 p.m. to 7:00 a.m., local time.
(e) “Noise” means the intensity, frequency, duration, and character of sound, including sound and vibration of sub-audible frequencies.
(f) “Noise pollution” means the presence of noise of sufficient loudness, character, and duration, which whether from a single source or multiple sources, is, or may be predicted with reasonable certainty to be, injurious to health or which unreasonably interferes with the proper enjoyment of property or with any lawful business or activity.
(g) “Person” means any individual, group of individuals, firm, partnership, voluntary association, or private, public, or municipal corporation, or political subdivision of the state, or department, bureau, agency, or instrument of federal, state, or local government, responsible for the use of property.
(h) “Plainly audible” means any sound produced by a radio, tape player, phonograph, disc player, computer, loud speaker, microphone or other mechanical sound-making device or instrument, including an amplified, acoustic or percussive instrument, that can be clearly heard by a person using his or her own normal hearing faculties. Any code enforcement or law enforcement officer who hears a sound that is plainly audible, as defined herein, shall be entitled to measure the sound according to the following standards:
(1) The primary means of detection shall be by means of the officer or code enforcement official’s ordinary auditory senses, so long as his hearing is not enhanced by any mechanical device, such as a hearing aid.
(2) The officer or code enforcement official need not determine the particular words or phrases being produced or the name of any song or artist producing the sound. The detection of a rhythmic bass reverberating-type sound is sufficient to constitute a plainly audible sound.
(3) The officer or code enforcement official must be able to determine the source or origin of the sound whether by direct line of sight from the affected residential property or by articulating such other reasonable basis for such determination if there is no direct line of sight confirmation of the source or origin of the sound.
(i) “Source” means any person or property, real or personal, contributing to noise pollution.
(j) “Zoning district” means an area within the city within which certain uniform regulations or requirements apply under the Frederick City Zoning Ordinance. For the purposes of this chapter, zoning districts shall be classified as follows:
(1) “Commercial” means zones BO, B1, B3, DBO and DB.
(2) “Industrial” means zones M1, M2 and MO.
(3) “Residential” means zones R-0, R-1, R-2, R-3, R-4, R-5, R-6, R-7, DR and DR-B. (Ord. No. G-02-9, § 1, 6-6-02; Ord. No. G-03-14, § 1, 7-17-03)

Editor’s note--This ordinance, as referenced in the introductory language of this section, is Ordinance No. G-02-9, adopted June 6, 2002, which added sections 15-21 through 15-21.8 to chapter 15.