Refrigerator compressor decibel levels

Living in an apartment with a refrigerator with a slowly failing compressor. Measured decibel readings today using Android Play Store app Noise Meter by JINASYS, one of four apps which partially met the criteria of the NIOSH Science Blog staff.

We measured our room noise levels with the refrigerator compressor on and off.

RESULTS

Refrigerator compressor ON

• 50.7dB - Six inches away (Noise level: Interior noise in car)
• 43.6dB - six feet away (Noise level: Library)
• 35.9dB - 13-14 feet away (Noise level: Whispering words)

Refrigerator compressor OFF

• 21.3dB - Six inches away (Noise level: Very calm room)
• 20.3dB - six feet away (Noise level: Very calm room)
• 20.6dB - 13-14 feet away (Noise level: Very calm room)

NOTES

• As the NIOSH Science Blog staff note, "Android devices are built by several different manufacturers and that there is a lack of conformity for using similar microphones and other audio components in their devices." In other words, "Android and Windows developers do not offer apps that meet the functionality needed for occupational noise assessments."
• Therefore, I can, at best, hope for a relative comparison between testings on the same hardware, with the caveat understood that the device may not reflect verified decibel levels
• The refrigerator in question represents a 10-year-old Maytag Performa PTB1753GR
• Maytag refrigerator Use and Care Guide - 61005299 (PDF; 15 pages; 1.3MB)...unfortunately, seems to say nothing about dB levels (via)
• This seems to indicate an increase in noise of 15-30dB with the refrigerator running
• Increase in noise levels (via):
• 1dB  –  Not noticable
• 3dB  –  Barely noticeable
• 5dB  –  Clearly noticeable change
• 10dB  –  About twice as loud
• 20dB  –  About four times as loud

Just how much noise should the refrigerator make under normal operating conditions? I see opinions online vary from 30-50 dB. 

How much does the characteristics of the noise matter? For example, whining noise versus white noise. Our refrigerator emits an continuous buzzing noise.

Previously