Extracted text (via pymupdf)
36004 characters
AZ Office CA Office 4960 S. Gilbert Road, Ste 1-461 1197 Los Angeles Avenue, Ste C-256 Chandler, AZ 85249 Simi Valley, CA 93065 p. (602) 774-1950 p. (805) 426-4477 www.mdacoustics.com MD Acoustics, LLC 1 JN: 02222307_Letter Report May 17, 2023 Mr. Luke Eid SSCW Companies 960 W. Behrend Drive, Suite 1 Phoenix, AZ 85027 Subject: SuperStar Express Car Wash at 51st & Olive – Noise Impact Study – City of Glendale, AZ Dear Mr. Schatz: MD Acoustics, LLC (MD) has completed a noise assessment for the proposed SuperStar Express Car Wash located at 5131 W Olive Avenue (APN:148-204-64A) in the City of Glendale, AZ. This assessment reviews the projected car wash operational noise levels and compares them to the City’s noise ordinance. The project proposes an approximately 130-foot car wash tunnel with 26 covered vacuum bays. 1.0 Assessment Overview This assessment evaluates the projections of operational noise and compares them to the City’s noise ordinance for informational purposes. The project location map is located in Exhibit A. The site plan utilized for the project is indicated in Exhibit B. The nearest residences are located approximately 80 feet to the east, 260 feet to the west, 550 feet to the south, and 670 feet to the northwest. There is a drive- through at the CVS directly north of the project site. 51st Avenue is to the east, and Olive Avenue is to the north. 2.0 Local Acoustical Requirements The City of Glendale does not have a specific not to exceed noise limit as it relates to stationary noise sources. However, Section 25-64 of the City of Glendale Municipal Code provides further information as it relates to the City’s noise ordinance and is as follows: Sec. 25-64. Excessive, unnecessary, or offensive noise prohibited. a) It shall be unlawful for any person to make or continue, or cause or permit to be made or continued, any excessive, unnecessary, or offensive noise that disturbs the peace and quiet or that causes discomfort or annoyance to two or more independent witnesses who are not related. b) This article is intended to reduce the amount of return visits by law enforcement. Subsequent visits by law enforcement will be cause for abatement of such disturbance and will require a mandatory restitution assessment for the law enforcement subsequent response services as a term of the sentencing. In an effort to provide a quantified analysis of the noise, this review assesses the project’s operational noise levels at adjacent sensitive uses. SuperStar Express Car Wash at 51st & Olive Noise Impact Study City of Glendale, AZ MD Acoustics, LLC 2 JN: 02222307_Letter Report Exhibit A Location Map Site SuperStar Express Car Wash at 51st & Olive Noise Impact Study City of Glendale, AZ MD Acoustics, LLC 3 JN: 02222307_Letter Report Exhibit B Site Plan SuperStar Express Car Wash at 51st & Olive Noise Impact Study City of Glendale, AZ MD Acoustics, LLC 4 JN: 02222307_Letter Report 3.0 Study Method and Procedure SoundPLAN Acoustic Model SoundPLAN (SP) acoustical modeling software was utilized to model future worst-case stationary noise impacts to the adjacent land uses. SP is capable of evaluating multiple stationary noise source impacts at various receiver locations. SP’s software utilizes algorithms (based on the inverse square law and reference equipment noise level data) to calculate noise level projections. The software allows the user to input specific noise sources, spectral content, sound barriers, building placement, topography, and sensitive receptor locations. The future worst-case noise level projections were modeled using referenced sound level data for the various stationary on-site sources (vacuums, vacuum turbine motors, and car wash blowers at the exit). The tunnel is approximately 130 feet long with a 10-foot-tall by 12-foot-wide exit and entrance opening. The blowers (a 14 MacNeil blower system or equivalent) were modeled at 10 feet high as point sources. The blowers will be located approximately 5 to 10 feet inside the exit of the tunnel. The reference equipment sound level data is provided in Appendix B. The SP model assumes a total of 26 vacuums and the dryer system are operating simultaneously (worst- case scenario) when in actuality the noise will be intermittent and lower in noise level. The reference vacuum equipment sound level data is provided in Appendix B. All other noise-producing equipment (e.g., compressors, pumps) will be housed within mechanical equipment rooms. 4.0 Findings and Recommendations Existing Exterior Noise Two (2) 15-minute ambient noise measurements were conducted at the project site on May 15th, 2023. The sound level meter measured the Leq, Lmin, Lmax, and other statistical data (e.g., L2, L8…). The noise measurements were taken to determine the existing ambient noise levels. Noise data indicates that traffic along Olive Avenue is the primary source of noise impacting the site and the adjacent uses. This assessment utilizes the ambient noise data as a basis and compares project operational levels to said data. The results of the short-term noise data are presented in Table 1. Table 1: Short-Term Noise Measurement Data (dBA)1 Location Start Time Stop Time Leq Lmax Lmin L(2) L(8) L(25) L(50) L(90) NM1 11:16 AM 11:31 AM 71.4 92.0 52.6 78.1 74.9 71.5 66.9 60.1 NM2 11:45 AM 12:00 PM 52.5 60.7 45.9 57.6 55.9 53.2 51.2 49.0 Notes: 1. Short-term noise monitoring locations are illustrated in Appendix A. Noise data indicates the ambient noise level is 53 to 71 dBA Leq near the project site and surrounding area. Additional field notes and photographs are provided in Appendix A. For this evaluation, MD has compared the project’s projected noise levels to the existing ambient level. SuperStar Express Car Wash at 51st & Olive Noise Impact Study City of Glendale, AZ MD Acoustics, LLC 5 JN: 02222307_Letter Report Future Exterior Noise Sensitive receptors affected by the project operational noise include existing residences to the east and west and a drive-thru window to the north. A total of three (3) receptors were modeled to accurately evaluate the future operational noise levels at the sensitive receptors. A yellow dot denotes a receptor. All yellow dots represent either a property line or a sensitive receptor, such as a sensitive outdoor area or building façade. Receptors 1 and 3 represent existing residential uses, and receptor 2 represents a pharmacy drive-through. Table 2 presents the measured ambient noise level, the project’s noise level, and the combined project plus ambient noise level condition. Table 2: Worst-Case Predicted Operational Noise Levels (dBA)1 Receptor1 Existing Ambient Noise Level (dBA, Leq)2 Project Noise Level (dBA, Leq)3 Total Combined Noise Level (dBA, Leq) Change in Noise Level as Result of Project 1 53 52 56 3 2 71 61 71 0 3 71 67 72 2 Notes: 1. Receptors 1 and 3 represent existing residential uses. Receptor 2 represents a drive-thru. 2. See Appendix A for the ambient noise measurement. 3. See Exhibit C for the operational noise level projections at said receptors. Exhibit C shows the future noise level projections and contours based on the proposed project design. The model indicates that the project-only noise level will be 52 to 67 dBA at the existing residential receptors and 63 dBA Leq at the nearby drive-through. The project will increase the existing ambient noise level by 0 to 3 dB at the sensitive receptors. The noise code does not specify a quantitative noise standard but instead prohibits unreasonably loud and disturbing noise. Table 3 provides the characteristics associated with changes in noise levels. Table 3: Change in Noise Level Characteristics Changes in Intensity Level, dBA Changes in Apparent Loudness 1 Not perceptible 3 Just perceptible 5 Clearly noticeable 10 Twice (or half) as loud https://www.fhwa.dot.gov/environMent/noise/regulations_and_guidance/polguide/polguide02.cfm It takes a change of 3 dB for the human ear to perceive a difference and a change of 5 dB to perceive a clearly noticeable difference. Therefore, the change in noise level would be “Not Perceptible” to “Just Perceptible” at the sensitive receptors. The impact is therefore less than significant. SuperStar Express Car Wash at 51st & Olive Noise Impact Study City of Glendale, AZ MD Acoustics, LLC 6 JN: 02222307_Letter Report 5.0 Conclusions MD is pleased to provide this noise review for the SuperStar Express Car Wash project. If you have any questions regarding this analysis, please call our office at (602) 774-1950. Sincerely, MD Acoustics, LLC Rachel Edelman Claire Pincock, INCE-USA Acoustical Consultant Acoustical Consultant SuperStar Express Car Wash at 51st & Olive Noise Impact Study City of Glendale, AZ MD Acoustics, LLC 7 JN: 02222307_Letter Report Exhibit C Operational Noise Levels Appendix A Field Sheet Appendix B Sound Reference Data Project: SuperStar Valencia Rd Tucson Job Number: 02222124 Site Address/Locati on: 1511 W Valencia Rd Date: 12/16/2021 Field Tech/Engineer: Robert Pearson Source/System: MacNeil Tech 21 - 15 Blowers General Locati on: Measured @ 5' Sound Meter: XL2 NTi SN: A2A-16164-E0 Setti ngs: Meteorological Cond.: Table 1: Summary Measurement Data Figure 1: Acousti c Spectrum - MacNeil Tech 21 - 15 Blowers Site Observati ons: Meter 5.5' off ground a 5' from edge of blower Leq Lmin Lmax 96.6 96.3 97.0 Ln 1 Ln 5 Ln 10 Ln 50 Ln 90 Ln 99 97.1 97.0 96.9 96.5 96.2 0.0 Source/System Overall Source Overall dB(A) 3rd Octave Band Data (dBA) 20 25 31.5 40 50 63 80 100 125 160 200 250 315 400 500 630 800 1k 12.5k1.6k 2k 2.5k 3.15k 4k 5k 6.3k 8k 10k 12.5k16k 20k MacNeil Tech 21 - 15 Blowers Car Wash Blowe 96.6 18.0 26.9 35.5 47.8 53.4 58.4 57.7 62.3 65.4 66.6 74.0 82.7 78.6 86.0 85.0 88.5 85.6 87.6 88.5 85.0 84.5 83.0 81.4 80.3 79.4 77.6 74.1 70.0 65.4 60.2 53.9 20 40 63 125 250 500 1k 2k 4k 8k 16k Freq (Hz) 0 20 40 60 80 100 Sound Pressure Level, dBA www.mdacoustics.com AZ Office 4960 S. Gilbert Rd, Ste 1-461 Chandler, AZ 85249 p. (602) 774-1950 CA Office 1197 Los Angeles Ave, Ste C-256 Simi Valley, CA 93065 p. (805) 426-4477 Project: SuperStar Car Wash Chula Vista Site Observations: Site Location: 1555 W Warner Rd, Gilbert, AZ 85233 Date: 4/5/2018 Field Tech/Engineer: Robert Pearson Source/System: Vacutec System Location: Vac Bay 1 Sound Meter: NTi XL2 SN: A2A-05967-E0 Settings: A-weighted, slow, 1-sec, 10-sec duration Meteorological Cond.: 80 degrees F, 2 mph wind 20 25 31.5 40 50 63 80 100 125 160 200 250 315 400 500 630 800 1K 1.25K 1.6K 2K 2.5K 3.15K 4K 5K 6.3K 8K 10K 12.5K 16K 20K Vacutech (Holstered) Vacuum 63.3 9 17 22 29 31 35 40 41 44 43 46 48 47 49 51 51 51 52 53 52 52 50 52 53 50 47 47 48 45 39 30 Vacutech (Unholstered) Vacuum 80.7 6 19 22 28 34 37 40 43 47 46 48 48 48 49 54 55 58 58 62 65 68 70 74 75 73 69 67 65 63 60 55 Vacutech (Inside Car) Vacuum 69.6 16 28 31 38 42 45 49 51 52 55 60 61 57 55 59 53 55 56 54 57 57 57 57 57 55 54 51 48 46 42 36 Average Level* Vacuum 76.3 13 24 28 34 38 41 45 47 49 51 56 57 53 52 56 54 56 56 59 61 64 66 69 70 68 64 62 60 58 55 50 * Refers to the logarithmic average of all measurements. This measurement represents an average of the multiple vacuum positions. Clear sky, measurements were performed within 1.5ft of source. Measurements were performed while the vacuum was positiioned at three (3) different positions. Holstered, unholstered and inside a car. This data is utilized for acoustic modeling purposes and represents an average sound level at a vacuum station. Table 1: Summary Measurement Data Source System Overall dB(A) 3rd Octave Band Data (dBA) Figure 1: Holstered Figure 2: Unholstered Figure 3: Inside Car Figure 1: Example Measurement Position 0 10 20 30 40 50 60 70 80 20 25 31.5 40 50 63 80 100 125 160 200 250 315 400 500 630 800 1K 1.25K 1.6K 2K 2.5K 3.15K 4K 5K 6.3K 8K 10K 12.5K 16K 20K dB Freq (Hz) 1.5ft from Nozzle Vacutech sound levels SOUND LEVEL METER READINGS MODEL: FT‐DD‐T340HP4 (40hp VACSTAR TURBINE VACUUM PRODUCER) READING ONE: 43 DB‐A, 3 FEET FROM TURBINE @ 45° ANGLE AND NO BACKGROUND NOISE OR OUTSIDE INTERFERENCE. READING TWO: 36 DB‐A, 10 FEET FROM TURBINE @ 45° ANGLE AND NO BACKGROUND NOISE OR OUTSIDE INTERFERENCE. READING THREE: 24 DB‐A, 20 FEET FROM TURBINE @ 45° ANGLE AND NO BACKGROUND NOISE OR OUTSIDE INTERFERENCE. READING FOUR: 12 DB‐A, 30 FEET FROM TURBINE @ 45° ANGLE AND NO BACKGROUND NOISE OR OUTSIDE INTERFERENCE. NOTE: THESE READINGS WERE TAKEN OUTSIDE OF 8’x10’x8’ CINDER BLOCK ENCLOSURE WITH CONCRETE SLAB AND WOOD JOIST ROOF. SOUND LEVEL METER USED: SIMPSON MODEL #40003 – MSHA APPROVED. MEETS OSHA & WALSH‐HEALY REQUIREMENTS FOR NOISE CONTROL. CONFORMS TO ANSI S1.4‐1983, IEC 651 SPECS FOR METER TYPE. Vacutech 1350 Hi-Tech Drive, Sheridan WY, 82801 PHONE: (800) 917-9444 FAX: (303) 675-1988 EMAIL: info@vacutechllc WEB SITE: vacutechllc.com Appendix C SoundPLAN Inputs/Outputs 02222307_SS 51st & Olive Contribution level - 001 - 14 MacnNeil - Standard: Outdoor SP 9 Source Source ty Leq,d dB(A) Receiver R1 Fl G Lr,lim dB(A) Leq,d 52.5 dB(A) Sigma(Leq,d) 0.0 dB(A) 001 - 14 MacnNeil - Standard Tunnel-Roof 01 Area 49.9 001 - 14 MacnNeil - Standard Tunnel-Transmissive area 01 Area 48.8 001 - 14 MacnNeil - Standard Tunnel-Transmissive area 01 Area 28.7 Vac Point 24.2 Vac Point 24.2 Vac Point 24.2 Vac Point 24.1 Vac Point 24.1 Vac Point 24.1 Vac Point 24.1 Vac Point 24.1 Vac Point 24.1 Vac Point 24.0 Vac Point 23.9 Vac Point 23.9 Vac Point 21.7 Vac Point 21.7 Vac Point 21.3 Car Lane Line 19.5 Car Lane Line 19.1 Car Lane Line 18.5 001 - 14 MacnNeil - Standard Tunnel-Facade 03 Area -4.2 001 - 14 MacnNeil - Standard Tunnel-Facade 04 Area -9.0 001 - 14 MacnNeil - Standard Tunnel-Facade 02 Area -10.6 001 - 14 MacnNeil - Standard Tunnel-Facade 01 Area -22.5 Receiver R2 Fl G Lr,lim dB(A) Leq,d 61.4 dB(A) Sigma(Leq,d) 0.0 dB(A) 001 - 14 MacnNeil - Standard Tunnel-Roof 01 Area 58.6 001 - 14 MacnNeil - Standard Tunnel-Transmissive area 01 Area 57.9 Vac Point 35.8 Vac Point 35.4 Vac Point 35.1 Vac Point 35.0 Vac Point 34.7 Vac Point 34.2 Vac Point 33.7 Vac Point 33.3 Vac Point 32.8 Vac Point 32.4 Vac Point 32.0 Vac Point 31.7 Vac Point 31.3 Vac Point 31.0 Vac Point 28.7 SoundPLAN 9.0 MD Acoustics LLC 4960 S. Gilbert Rd Chandler, AZ 85249 Phone: 602 774 1950 1 02222307_SS 51st & Olive Contribution level - 001 - 14 MacnNeil - Standard: Outdoor SP 9 Source Source ty Leq,d dB(A) 001 - 14 MacnNeil - Standard Tunnel-Transmissive area 01 Area 27.1 Car Lane Line 26.8 Car Lane Line 26.6 Car Lane Line 26.4 001 - 14 MacnNeil - Standard Tunnel-Facade 03 Area 5.4 001 - 14 MacnNeil - Standard Tunnel-Facade 04 Area -0.1 001 - 14 MacnNeil - Standard Tunnel-Facade 02 Area -1.7 001 - 14 MacnNeil - Standard Tunnel-Facade 01 Area -15.5 Receiver R3 Fl G Lr,lim dB(A) Leq,d 67.2 dB(A) Sigma(Leq,d) 0.0 dB(A) 001 - 14 MacnNeil - Standard Tunnel-Transmissive area 01 Area 65.6 001 - 14 MacnNeil - Standard Tunnel-Roof 01 Area 62.3 001 - 14 MacnNeil - Standard Tunnel-Transmissive area 01 Area 33.3 Vac Point 32.7 Car Lane Line 27.6 Car Lane Line 27.0 Car Lane Line 26.2 Vac Point 22.0 Vac Point 20.5 Vac Point 19.3 Vac Point 18.3 Vac Point 17.7 Vac Point 17.1 Vac Point 17.0 Vac Point 16.8 Vac Point 16.3 Vac Point 16.0 Vac Point 15.9 Vac Point 15.8 Vac Point 15.8 Vac Point 15.7 001 - 14 MacnNeil - Standard Tunnel-Facade 02 Area 14.1 001 - 14 MacnNeil - Standard Tunnel-Facade 03 Area 10.1 001 - 14 MacnNeil - Standard Tunnel-Facade 04 Area 0.9 001 - 14 MacnNeil - Standard Tunnel-Facade 01 Area -10.7 SoundPLAN 9.0 MD Acoustics LLC 4960 S. Gilbert Rd Chandler, AZ 85249 Phone: 602 774 1950 2 02222307_SS 51st & Olive Octave spectra of the sources in dB(A) - 001 - 14 MacnNeil - Standard: Outdoor SP 3 Name Source type l or A m,m² Li dB(A) R'w dB L'w dB(A) Lw dB(A) KI dB KT dB DO-Wall dB Emission spectrum 63Hz dB(A) 125Hz dB(A) 250Hz dB(A) 500Hz dB(A) 1kHz dB(A) 2kHz dB(A) 4kHz dB(A) 8kHz dB(A) 001 - 14 MacnNeil - Standard Tunnel-Facade 01 Area 25.05 82.9 57.0 29.1 43.1 0.0 0.0 3 336_Facade 01 33.7 28.3 36.7 40.6 30.6 24.9 17.6 10.6 001 - 14 MacnNeil - Standard Tunnel-Facade 02 Area 244.68 86.6 57.0 32.6 56.5 0.0 0.0 3 337_Facade 02 47.0 41.6 50.0 53.9 44.2 38.6 31.9 27.0 001 - 14 MacnNeil - Standard Tunnel-Facade 03 Area 25.05 91.2 57.0 37.0 51.0 0.0 0.0 3 338_Facade 03 41.4 36.0 44.4 48.4 38.8 33.5 27.0 23.0 001 - 14 MacnNeil - Standard Tunnel-Facade 04 Area 244.68 86.6 57.0 32.6 56.5 0.0 0.0 3 339_Facade 04 47.0 41.6 50.0 53.9 44.2 38.6 31.9 27.0 001 - 14 MacnNeil - Standard Tunnel-Roof 01 Area 291.58 86.6 0.0 86.6 111.3 0.0 0.0 0 334_Roof 01_ 77.6 86.2 96.6 106.6 106.0 104.6 101.0 94.6 001 - 14 MacnNeil - Standard Tunnel-Transmissive area 01 Area 17.85 93.3 0.0 93.3 105.8 0.0 0.0 3 306_Transmissive area 01_ 72.0 80.6 91.0 101.0 100.4 99.1 95.7 89.8 001 - 14 MacnNeil - Standard Tunnel-Transmissive area 01 Area 17.85 82.7 0.0 82.7 95.2 0.0 0.0 3 304_Transmissive area 01_ 62.0 70.5 80.9 90.8 90.0 88.2 84.0 75.1 Car Lane Line 41.60 62.8 79.0 0.0 0.0 0 Drive-Thru - Idiling Car @ 6ft 63.0 64.5 68.0 71.7 72.6 73.8 70.2 62.1 Car Lane Line 31.03 62.8 77.7 0.0 0.0 0 Drive-Thru - Idiling Car @ 6ft 61.7 63.2 66.7 70.4 71.3 72.5 69.0 60.8 Car Lane Line 34.96 62.8 78.2 0.0 0.0 0 Drive-Thru - Idiling Car @ 6ft 62.3 63.8 67.3 71.0 71.8 73.0 69.5 61.3 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 Vac Point 81.0 81.0 0.0 0.0 0 Vacutech - in car 61.6 69.0 76.6 72.9 71.4 73.2 72.6 67.6 SoundPLAN 9.0 MD Acoustics LLC 4960 S. Gilbert Rd Chandler, AZ 85249 Phone: 602 774 1950 1 02222307_SS 51st & Olive Contribution spectra - 001 - 14 MacnNeil - Standard: Outdoor SP 23 Time slice Sum dB(A) 25Hz dB(A) 31.5Hz dB(A) 40Hz dB(A) 50Hz dB(A) 63Hz dB(A) 80Hz dB(A) 100Hz dB(A) 125Hz dB(A) 160Hz dB(A) 200Hz dB(A) 250Hz dB(A) 315Hz dB(A) 400Hz dB(A) 500Hz dB(A) 630Hz dB(A) 800Hz dB(A) 1kHz dB(A) 1.25kHz dB(A) 1.6kHz dB(A) 2kHz dB(A) 2.5kHz dB(A) 3.15kHz dB(A) 4kHz dB(A) 5kHz dB(A) 6.3kHz dB(A) 8kHz dB(A) 10kHz dB(A) 12.5kHz dB(A) 16kHz dB(A) 20kHz dB(A) Receiver R1 Fl G Lr,lim dB(A) Leq,d 52.5 dB(A) Sigma(Leq,d) 0.0 dB(A) Leq,d -22.5 -25.5 -36.2 -30.3 -28.9 -40.0 -36.6 -49.8 -75.0 Leq,d -10.6 -13.4 -24.4 -18.8 -17.4 -23.9 -27.2 -40.5 -61.5 Leq,d -4.2 -10.5 -19.1 -11.0 -7.5 -17.2 -24.0 -35.1 -51.9 Leq,d -9.0 -12.3 -22.8 -16.5 -14.6 -25.1 -31.7 -42.9 -59.8 Leq,d 49.9 22.3 27.5 37.2 45.9 44.9 42.7 32.9 11.8 Leq,d 48.8 21.0 26.0 34.6 44.9 44.0 41.6 33.4 14.6 Leq,d 28.7 -1.4 0.7 7.7 15.4 15.9 27.7 17.6 -10.0 Leq,d 19.5 -1.8 -18.8 -12.9 2.1 3.0 5.0 -0.5 3.4 0.2 3.9 -1.0 0.9 5.3 5.3 9.2 7.1 9.0 9.6 8.6 10.8 10.6 5.9 1.5 -4.8 -12.5 -21.0 -32.8 -46.2 -62.9 -81.8 Leq,d 18.5 -2.7 -19.7 -13.8 1.2 2.1 4.1 -1.4 2.5 -0.6 3.1 -1.9 0.0 4.5 4.4 8.3 6.3 7.8 8.5 7.5 9.6 9.4 4.8 0.5 -5.8 -13.4 -21.9 -33.6 -47.2 -64.0 -83.1 Leq,d 19.1 -2.4 -19.3 -13.4 1.6 2.5 4.5 -1.0 2.9 -0.3 3.4 -1.6 0.4 4.8 4.8 8.7 8.1 8.4 9.0 8.0 10.2 10.0 5.3 1.0 -5.3 -13.1 -21.6 -33.5 -47.3 -64.3 -83.6 Leq,d 21.7 -14.0 -11.0 -4.1 -0.1 2.9 6.8 5.4 6.3 9.2 11.9 12.9 8.9 7.1 11.1 5.0 6.9 9.6 7.1 11.1 10.2 9.1 7.4 5.1 -0.2 -5.7 -14.9 -26.3 -39.3 -57.7 -81.3 Leq,d 21.3 -14.1 -11.1 -4.1 -0.2 2.8 6.7 5.3 6.2 9.1 11.8 12.8 8.8 7.0 11.0 4.9 6.8 8.6 6.1 10.1 9.2 8.1 6.4 4.6 -0.6 -6.1 -15.2 -26.6 -39.7 -58.2 -82.0 Leq,d 21.7 -14.0 -11.0 -4.0 0.0 2.9 6.9 5.4 6.4 9.3 12.0 13.0 9.0 7.3 11.2 5.2 7.0 8.8 7.0 11.1 10.3 9.1 7.4 5.1 -0.1 -5.6 -14.7 -26.0 -38.9 -57.1 -80.6 Leq,d 24.1 -13.5 -10.5 -3.6 0.4 3.4 7.3 8.2 9.2 12.1 15.0 15.9 11.9 10.2 14.2 8.1 9.8 10.4 8.7 12.7 11.8 10.6 9.0 6.9 1.9 -3.2 -11.9 -22.6 -35.1 -52.7 -75.5 Leq,d 24.1 -13.5 -10.6 -3.6 0.4 3.3 7.3 8.2 9.1 12.1 15.0 15.9 11.9 10.2 14.2 8.0 9.8 10.3 8.7 12.6 11.8 10.6 9.0 6.8 1.8 -3.3 -12.0 -22.8 -35.3 -52.9 -75.7 Leq,d 24.1 -13.6 -10.6 -3.6 0.3 3.3 7.3 8.2 9.1 12.1 14.9 15.8 11.8 10.0 14.0 7.9 9.7 10.2 9.0 13.0 12.1 11.0 9.3 7.1 2.0 -3.3 -12.1 -22.9 -35.5 -53.3 -76.2 Leq,d 24.1 -13.5 -10.5 -3.5 0.4 3.4 7.4 8.3 9.2 12.1 15.0 16.0 11.9 10.2 14.2 8.1 9.8 10.4 7.9 12.1 11.3 10.1 9.6 7.3 2.2 -3.0 -11.7 -22.5 -34.9 -52.5 -75.1 Leq,d 24.1 -13.5 -10.5 -3.5 0.4 3.4 7.4 8.3 9.2 12.1 15.0 16.0 11.9 10.2 14.2 8.1 9.8 10.4 7.9 12.2 11.4 10.2 9.6 7.3 2.2 -3.0 -11.7 -22.5 -34.9 -52.5 -75.2 Leq,d 24.1 -13.5 -10.5 -3.5 0.4 3.4 7.3 8.3 9.2 12.1 15.0 16.0 11.9 10.3 14.2 8.1 9.8 10.4 8.6 12.6 11.7 10.6 9.5 7.3 2.2 -3.0 -11.8 -22.6 -35.0 -52.6 -75.3 Leq,d 24.0 -13.8 -10.8 -3.8 0.2 3.1 9.4 7.9 8.9 11.8 14.6 15.6 11.5 9.8 13.8 7.7 9.5 10.0 9.1 13.1 12.3 11.1 9.5 7.2 2.0 -3.4 -12.5 -23.6 -36.5 -54.6 -77.9 Leq,d 23.9 -13.8 -10.9 -3.9 0.1 3.1 9.3 7.9 8.8 11.8 14.5 15.5 11.4 9.7 13.7 7.6 9.4 10.0 8.7 12.7 11.8 10.7 9.1 6.8 1.7 -3.6 -12.6 -23.8 -36.8 -55.0 -78.4 Leq,d 23.9 -13.9 -10.9 -3.9 0.0 3.0 9.2 7.8 8.7 11.7 14.5 15.5 11.4 9.9 13.8 7.6 9.5 10.1 8.8 12.7 11.8 10.6 9.0 6.8 1.6 -3.7 -12.8 -24.0 -37.0 -55.4 -78.9 Leq,d 24.2 -13.6 -10.6 -3.7 0.3 3.3 7.2 8.1 9.0 12.0 14.8 15.8 11.7 10.1 14.1 7.9 9.7 10.2 9.5 13.5 12.6 11.4 9.8 7.4 2.2 -3.2 -12.1 -23.1 -35.7 -53.6 -76.5 Leq,d 24.2 -13.7 -10.7 -3.7 0.3 3.2 7.2 8.1 9.0 12.0 14.8 15.7 11.7 10.0 13.9 7.9 9.6 10.2 9.4 13.5 12.6 11.4 9.7 7.4 2.2 -3.2 -12.2 -23.2 -36.0 -53.9 -77.0 Leq,d 24.2 -13.7 -10.7 -3.8 0.2 3.2 9.4 8.0 8.9 11.9 14.7 15.6 11.6 9.9 13.8 7.8 9.5 10.1 9.4 13.4 12.6 11.4 9.7 7.4 2.2 -3.3 -12.3 -23.4 -36.2 -54.2 -77.4 Receiver R2 Fl G Lr,lim dB(A) Leq,d 61.4 dB(A) Sigma(Leq,d) 0.0 dB(A) Leq,d -15.5 -17.3 -28.6 -24.3 -23.7 -34.7 -42.5 -53.2 -69.8 Leq,d -1.7 -4.5 -14.8 -11.0 -9.7 -11.1 -16.2 -26.8 -44.5 Leq,d 5.4 -0.4 -7.7 -3.5 1.8 -5.1 -10.4 -18.7 -28.9 Leq,d -0.1 -2.8 -12.8 -8.1 -6.8 -17.6 -24.8 -34.6 -47.1 Leq,d 58.6 27.9 34.3 44.6 54.2 54.1 51.6 44.7 29.4 Leq,d 57.9 30.4 37.0 39.9 50.7 53.8 52.8 47.1 34.7 Leq,d 27.1 9.1 11.3 15.6 22.6 22.1 19.5 12.4 -5.6 Leq,d 26.8 0.1 -16.9 -9.6 5.8 6.7 8.7 3.4 7.3 4.2 7.4 2.4 4.3 9.3 9.3 13.2 14.2 14.6 15.8 15.7 19.1 20.5 16.7 13.5 8.5 2.4 -4.2 -13.8 -24.9 -39.1 -55.2 Leq,d 26.4 -1.7 -18.7 -10.2 4.8 5.8 7.8 2.6 6.6 3.6 6.9 1.9 3.9 8.8 8.8 12.7 13.6 14.2 15.4 15.4 19.0 20.1 16.3 13.1 8.0 1.8 -4.8 -14.6 -26.0 -40.5 -56.9 SoundPLAN 9.0 MD Acoustics LLC 4960 S. Gilbert Rd Chandler, AZ 85249 Phone: 602 774 1950 1 02222307_SS 51st & Olive Contribution spectra - 001 - 14 MacnNeil - Standard: Outdoor SP 23 Time slice Sum dB(A) 25Hz dB(A) 31.5Hz dB(A) 40Hz dB(A) 50Hz dB(A) 63Hz dB(A) 80Hz dB(A) 100Hz dB(A) 125Hz dB(A) 160Hz dB(A) 200Hz dB(A) 250Hz dB(A) 315Hz dB(A) 400Hz dB(A) 500Hz dB(A) 630Hz dB(A) 800Hz dB(A) 1kHz dB(A) 1.25kHz dB(A) 1.6kHz dB(A) 2kHz dB(A) 2.5kHz dB(A) 3.15kHz dB(A) 4kHz dB(A) 5kHz dB(A) 6.3kHz dB(A) 8kHz dB(A) 10kHz dB(A) 12.5kHz dB(A) 16kHz dB(A) 20kHz dB(A) Leq,d 26.6 -1.4 -18.3 -10.4 5.1 6.1 8.2 2.9 6.9 3.9 7.1 2.2 4.1 8.5 8.9 12.8 13.9 14.4 15.7 15.7 19.3 20.3 16.4 13.1 8.0 1.7 -5.1 -15.0 -26.6 -41.4 -58.3 Leq,d 31.0 -12.4 -9.4 0.0 4.0 7.1 11.1 10.0 11.1 16.4 18.9 20.0 16.0 14.2 18.1 12.1 16.2 17.4 15.6 20.5 21.0 21.7 21.6 20.5 16.7 13.0 5.9 -3.0 -13.3 -28.4 -48.1 Leq,d 28.7 -12.6 -9.6 -0.2 3.8 6.8 10.9 9.8 10.8 13.8 16.3 17.5 13.4 11.6 15.5 9.4 13.6 15.2 13.4 18.3 18.8 19.6 19.1 17.9 14.1 10.3 3.1 -5.9 -16.4 -31.6 -51.5 Leq,d 31.3 -12.3 -9.3 0.2 4.2 7.2 11.2 10.3 11.3 16.7 19.2 20.3 16.3 14.5 18.5 12.4 16.4 17.6 15.9 20.8 21.3 22.0 21.9 20.8 17.1 13.4 6.4 -2.3 -12.4 -27.2 -46.5 Leq,d 35.4 -9.9 -6.9 0.1 4.1 9.6 13.6 13.3 15.8 19.7 22.7 23.8 19.8 18.0 22.0 15.9 21.6 23.6 22.0 26.3 26.0 25.7 25.1 24.3 21.0 18.1 12.3 5.1 -2.7 -14.4 -29.9 Leq,d 35.0 -10.3 -7.3 -0.3 3.8 9.2 13.2 12.9 14.0 19.2 22.3 23.4 19.3 17.6 21.6 15.5 20.5 22.5 21.3 25.9 25.7 25.3 24.8 23.9 20.6 17.6 11.6 4.3 -3.7 -15.7 -31.7 Leq,d 34.2 -10.8 -7.8 -0.7 5.7 8.7 12.8 12.3 13.3 18.7 21.6 22.7 18.7 16.9 20.9 14.8 19.2 20.7 19.7 24.9 25.1 24.8 24.2 23.3 19.9 16.8 10.6 3.0 -5.4 -17.9 -34.4 Leq,d 35.1 -4.2 -1.2 5.8 9.8 12.8 19.2 18.8 19.8 22.8 22.0 23.0 19.0 17.2 21.2 15.1 21.9 23.0 21.0 25.2 25.0 24.7 24.2 23.5 20.3 17.7 12.2 5.6 -1.4 -12.0 -26.3 Leq,d 34.7 -4.6 -1.6 5.4 9.4 12.4 18.8 18.5 19.5 22.5 21.5 22.5 18.5 16.7 20.7 14.7 21.6 22.5 20.6 24.8 24.6 24.3 23.8 23.0 19.9 17.1 11.6 4.8 -2.4 -13.3 -27.9 Leq,d 35.8 -9.6 -6.6 0.5 4.5 9.9 14.0 13.7 16.1 20.0 23.1 24.2 20.2 18.4 22.4 16.3 22.3 24.2 22.4 26.6 26.4 26.0 25.5 24.7 21.5 18.6 12.9 5.9 -1.7 -13.1 -28.3 Leq,d 32.4 -11.6 -8.6 -1.6 4.8 7.9 11.9 11.1 12.1 17.5 20.2 21.3 17.3 15.5 19.5 13.4 17.4 18.6 17.0 21.9 22.6 23.2 22.9 21.9 18.3 14.9 8.3 0.0 -9.3 -23.0 -41.1 Leq,d 32.0 -11.9 -8.8 -1.8 4.6 7.6 11.6 10.8 11.8 17.2 19.9 21.0 16.9 15.2 19.1 13.1 17.1 18.3 16.6 21.5 22.1 22.8 22.5 21.5 17.9 14.4 7.6 -0.8 -10.4 -24.4 -43.0 Leq,d 31.7 -12.0 -9.0 0.4 4.4 7.5 11.5 10.6 11.6 17.0 19.6 20.7 16.6 14.9 18.8 12.8 16.8 18.0 16.3 21.2 21.7 22.4 22.3 21.2 17.5 14.0 7.1 -1.4 -11.2 -25.6 -44.4 Leq,d 33.7 -11.0 -8.0 -1.0 5.5 8.5 12.5 12.0 13.0 18.4 21.3 22.4 18.3 16.6 20.5 14.5 18.6 20.0 18.8 24.0 24.5 24.6 23.9 23.0 19.5 16.3 10.0 2.3 -6.3 -19.1 -36.0 Leq,d 33.3 -11.2 -8.2 -1.2 5.3 8.3 12.3 11.7 12.7 18.0 20.9 22.0 18.0 16.2 20.2 14.1 18.1 19.4 18.2 23.1 24.0 24.1 23.6 22.6 19.1 15.8 9.4 1.5 -7.3 -20.4 -37.7 Leq,d 32.8 -11.4 -8.4 -1.4 5.0 8.0 12.1 11.4 12.4 17.7 20.5 21.6 17.6 15.8 19.8 13.7 17.7 19.3 17.7 22.6 23.3 23.7 23.3 22.3 18.7 15.3 8.8 0.7 -8.4 -21.9 -39.6 Receiver R3 Fl G Lr,lim dB(A) Leq,d 67.2 dB(A) Sigma(Leq,d) 0.0 dB(A) Leq,d -10.7 -13.3 -23.6 -18.9 -17.2 -27.2 -35.1 -46.1 -61.0 Leq,d 14.1 5.6 -1.2 6.0 11.4 3.9 -1.4 -9.4 -19.1 Leq,d 10.1 1.3 -5.1 1.9 7.3 0.5 -4.8 -12.5 -20.9 Leq,d 0.9 -1.1 -12.0 -7.7 -7.0 -18.0 -25.0 -34.2 -45.0 Leq,d 62.3 31.8 37.3 47.6 57.4 57.6 55.8 50.4 38.0 Leq,d 65.6 30.9 37.5 47.0 58.2 61.1 60.6 56.0 45.6 Leq,d 33.3 13.2 16.5 21.3 28.9 28.9 25.3 17.6 0.9 Leq,d 27.6 2.0 -15.1 -9.3 6.1 8.3 10.2 5.3 9.1 5.9 9.3 4.2 6.0 10.2 10.1 14.0 14.6 15.1 16.4 16.2 19.9 21.2 17.4 14.4 9.8 4.4 -1.2 -9.4 -18.4 -29.8 -42.4 Leq,d 26.2 0.2 -16.8 -10.9 4.5 6.8 8.7 3.7 7.5 4.4 7.7 2.6 4.4 8.6 8.5 12.4 13.2 13.7 15.0 15.0 18.8 19.7 15.9 12.8 8.1 2.5 -3.4 -12.0 -21.6 -33.8 -47.4 Leq,d 27.0 0.4 -16.6 -10.7 4.6 7.3 9.3 4.3 8.2 5.1 8.4 3.4 5.3 9.5 9.4 13.3 13.9 14.5 15.9 16.0 19.8 20.6 16.8 13.7 9.0 3.3 -2.6 -11.3 -21.0 -33.4 -47.0 Leq,d 17.0 -10.9 -8.4 -2.0 2.6 4.8 7.9 6.1 6.0 7.7 8.9 8.4 3.1 -0.2 2.5 -4.7 -2.3 -2.5 -5.2 -1.2 -1.7 -2.3 -2.1 -3.8 -7.9 -11.6 -18.4 -26.6 -35.8 -49.4 -67.3 Leq,d 20.5 -11.0 -8.5 -2.0 2.3 4.7 8.0 6.5 6.8 9.0 9.3 9.4 4.5 1.6 4.7 -1.7 6.2 8.6 6.3 10.6 10.0 9.3 8.2 6.4 1.8 -3.0 -11.3 -21.0 -31.2 -45.3 -63.6 Leq,d 15.8 -11.7 -9.4 -3.1 1.5 3.6 6.6 4.7 4.5 6.1 7.5 7.1 1.8 -1.5 1.3 -5.8 -3.6 -3.3 -5.7 -1.7 -2.2 -2.7 -2.6 -4.1 -8.0 -11.5 -18.1 -26.1 -35.2 -48.5 -66.1 Leq,d 18.3 -10.2 -7.9 0.0 3.2 5.4 8.4 7.0 6.9 8.7 10.4 10.0 4.7 1.5 4.4 -2.7 -0.1 0.1 -2.4 1.4 0.8 0.3 -0.5 -1.4 -4.8 -7.8 -13.6 -20.7 -28.2 -39.5 -54.6 Leq,d 17.7 -10.9 -8.5 -0.6 2.6 4.7 7.8 6.3 6.2 7.9 9.9 9.5 4.1 0.9 3.6 -3.5 -1.3 -1.1 -3.5 0.3 -0.1 -0.6 -1.3 -2.2 -5.5 -8.4 -14.3 -21.3 -28.9 -40.4 -55.6 Leq,d 17.1 -11.6 -9.3 -1.3 1.9 4.1 7.1 5.6 5.4 7.1 9.3 8.8 3.7 0.5 3.4 -3.7 -1.8 -1.3 -3.7 0.3 -0.1 -0.6 -1.2 -2.2 -5.6 -8.6 -14.6 -22.0 -29.9 -41.7 -57.3 Leq,d 32.7 -4.5 -1.5 6.5 10.5 13.5 17.5 17.2 18.2 19.1 20.1 21.0 16.9 15.0 19.0 12.9 19.4 20.6 18.5 22.6 22.4 22.1 21.6 20.9 17.7 15.0 9.4 2.6 -4.6 -15.6 -30.4 Leq,d 22.0 -8.2 -5.5 2.1 5.6 8.1 11.5 10.5 10.8 13.0 13.4 13.4 8.3 5.3 8.3 1.3 6.0 6.1 3.2 6.6 5.7 4.7 3.5 2.2 -1.5 -4.8 -10.8 -18.0 -25.6 -36.9 -51.9 Leq,d 19.3 -9.3 -6.9 0.8 4.1 6.3 9.4 8.1 8.1 9.9 11.2 10.8 5.5 2.4 5.3 -1.8 1.5 1.6 -1.0 2.6 2.0 1.3 0.4 -0.6 -4.1 -7.1 -12.9 -20.0 -27.5 -38.7 -53.6 SoundPLAN 9.0 MD Acoustics LLC 4960 S. Gilbert Rd Chandler, AZ 85249 Phone: 602 774 1950 2 02222307_SS 51st & Olive Contribution spectra - 001 - 14 MacnNeil - Standard: Outdoor SP 23 Time slice Sum dB(A) 25Hz dB(A) 31.5Hz dB(A) 40Hz dB(A) 50Hz dB(A) 63Hz dB(A) 80Hz dB(A) 100Hz dB(A) 125Hz dB(A) 160Hz dB(A) 200Hz dB(A) 250Hz dB(A) 315Hz dB(A) 400Hz dB(A) 500Hz dB(A) 630Hz dB(A) 800Hz dB(A) 1kHz dB(A) 1.25kHz dB(A) 1.6kHz dB(A) 2kHz dB(A) 2.5kHz dB(A) 3.15kHz dB(A) 4kHz dB(A) 5kHz dB(A) 6.3kHz dB(A) 8kHz dB(A) 10kHz dB(A) 12.5kHz dB(A) 16kHz dB(A) 20kHz dB(A) Leq,d 15.9 -12.3 -10.0 -3.8 1.2 3.3 6.2 4.5 4.2 5.9 8.0 7.6 2.3 -1.0 1.8 -5.4 -3.4 -2.9 -5.2 -1.2 -1.6 -2.1 -2.8 -3.2 -7.0 -10.3 -16.7 -24.3 -32.8 -45.3 -62.0 Leq,d 15.8 -12.2 -9.9 -3.7 1.2 3.3 6.2 4.4 4.2 5.8 7.8 7.4 2.1 -1.2 1.6 -5.6 -3.3 -2.8 -5.2 -1.1 -1.5 -2.0 -2.8 -3.8 -7.4 -10.8 -17.1 -24.9 -33.6 -46.4 -63.3 Leq,d 15.7 -12.0 -9.7 -3.4 1.3 3.4 6.4 4.5 4.2 5.9 7.7 7.3 1.9 -1.3 1.5 -5.7 -3.3 -2.9 -5.2 -1.1 -1.6 -2.0 -2.8 -4.0 -7.6 -11.0 -17.5 -25.4 -34.2 -47.2 -64.5 Leq,d 16.8 -11.9 -9.6 -1.5 1.7 3.8 6.8 5.2 5.0 6.7 8.9 8.5 3.4 0.2 3.1 -4.0 -2.2 -1.7 -4.0 0.0 -0.4 -0.8 -1.5 -2.5 -5.9 -9.0 -15.0 -22.5 -30.5 -42.5 -58.4 Leq,d 16.3 -12.2 -9.9 -1.8 1.4 3.5 6.5 4.9 4.7 6.3 8.6 8.2 2.8 -0.5 2.3 -4.9 -3.1 -2.6 -4.9 -1.0 -1.4 -1.8 -2.5 -3.3 -6.7 -9.8 -15.8 -23.2 -31.4 -43.5 -59.6 Leq,d 16.0 -12.3 -10.0 -3.8 1.3 3.3 6.3 4.7 4.4 6.1 8.3 7.9 2.5 -0.8 2.0 -5.1 -3.4 -2.9 -5.2 -1.3 -1.6 -2.1 -2.8 -3.5 -6.9 -10.1 -16.3 -23.8 -32.1 -44.5 -60.9 SoundPLAN 9.0 MD Acoustics LLC 4960 S. Gilbert Rd Chandler, AZ 85249 Phone: 602 774 1950 3 Appendix D Glossary of Acoustical Terms Glossary of Terms A-Weighted Sound Level: The sound pressure level in decibels as measured on a sound level meter using the A-weighted filter network. The A-weighting filter de-emphasizes the very low and very high frequency components of the sound in a manner similar to the response of the human ear. A numerical method of rating human judgment of loudness. Ambient or Background Noise Level: The composite of noise from all sources, near and far. In this context, the ambient noise level constitutes the normal or existing level of environmental noise at a given location. Decibel (dB): A unit for measuring the amplitude of a sound, equal to 20 times the logarithm to the base 10 of the ratio of the pressure of the sound measured to the reference pressure, which is 20 micro-pascals. dB(A): A-weighted sound level (see definition above). Equivalent Sound Level (LEQ): The sound level corresponding to a steady noise level over a given sample period with the same amount of acoustic energy as the actual time varying noise level. The energy average noise level during the sample period. Human Sensitivity to Sound: In general, the healthy human ear can hear between 20 Hz to 20,000 Hz. Frequencies below 125 Hz are typically associated with low frequencies or bass. Frequencies between 125 Hz and 5,000 Hz are typically associated with mid-range tones. Finally, frequencies between 5,000 and 20,000Hz are typically associated with higher range tones. The human ear is sensitive to changes in noise levels, depending on the frequency. Generally speaking, the healthy human ear is most sensitive to sounds between 1,000 Hz and 5,000 Hz (A- weighted scale) and perceives a sound within that range as being more intense than a sound with a higher or lower frequency with the same magnitude. At lower and higher frequencies, the ear can become less sensitive depending on a number of factors. Figure 1 provides common indoor/outdoor noise levels. Figure 2 provides a brief summary of how humans perceive changes in noise levels. Figure 1 Day-Night Level (LDN or DNL): LDN is the average noise level over a 24-hour period. The noise between the hours of 10PM to 7AM is artificially increased by 10 dB. This noise is weighted to take into account the decrease in community background noise of 10 dB during this period. Noise: Any unwanted sound or sound which is undesirable because it interferes with speech and hearing, or is intense enough to damage hearing, or is otherwise annoying. The State Noise Control Act defines noise as "...excessive undesirable sound...". Sound Level (Noise Level): The weighted sound pressure level obtained by use of a sound level meter having a standard frequency-filter for attenuating part of the sound spectrum. Sound Level Meter: An instrument, including a microphone, an amplifier, an output meter, and frequency weighting networks for the measurement and determination of noise and sound levels.