Do phone decibel meters work?
What is a phone decibel meter?
A phone decibel meter is an application that uses your smartphone’s built-in microphone to measure sound levels and display them in decibels (dB). These apps turn your phone into a handy sound level meter that you can carry in your pocket.
Decibel meter apps measure sound by analyzing the audio input from your phone’s microphone. The app captures the sound waves, processes the audio data, and converts the measurements into dB units on your screen (cite: https://www.reddit.com/r/audioengineering/comments/qa5va5/how_accurate_are_smartphone_decibel_meter_apps/). Some apps simply show the instantaneous sound level, while more advanced apps can log measurements over time, show historical data, frequency analysis, and more.
Features may include setting different weighting filters like A, C, or Z; selecting fast or slow response times; calibrating the measurement; and customizing the measurement range. Popular decibel meter apps include SoundMeter, Decibel X, and SoundPrint (cite: https://www.healthyhearing.com/report/47805-The-best-phone-apps-to-measure-noise-levels). Using these apps transforms your smartphone into a handy sound level meter.
Measuring decibel levels
Decibels (dB) are a logarithmic unit used to measure the intensity of sound. The decibel scale ranges from 0 dB, the threshold of human hearing, to over 140 dB, the threshold of pain. A 10 dB increase represents a 10-fold increase in sound intensity. This means a sound measured at 70 dB has 10 times the sound energy of one measured at 60 dB.
Decibel levels correlate to the loudness of different sounds. For reference, a soft whisper is about 30 dB while a motorcycle engine running is around 95 dB. Prolonged exposure to sounds over 70 dB can cause hearing damage over time. Below are some common decibel levels (source):
- Babbling brook: 40 dB
- Refrigerator humming: 40 dB
- Normal conversation: 60 dB
- City traffic: 85 dB
- Motorcycle: 95 dB
- Power saw: 105 dB
As a reference, occupational noise exposure limits are 85 dB for 8 hours or 90 dB for 2 hours before hearing damage can occur (source). Understanding decibel measurements is key for evaluating potential hearing risk.
Accuracy of phone decibel meters
Several recent studies have tested the accuracy of smartphone decibel meter apps compared to professional sound level meters. A 2016 study published in Applied Acoustics tested 10 Android and iOS apps using various phones and tablets (Murphy, 2016). They found that iOS apps overestimated true noise levels by 2.93 dB on average, while Android apps underestimated by 1.44 dB. The apps were generally within 3 dB of a class 1 sound level meter.
Researchers from the National Institute for Occupational Safety and Health (NIOSH) also evaluated smartphone sound measurement apps (NIOSH, 2014). They tested apps on the iPhone 4S and Galaxy SIII, finding measurements were within 1 dB of a reference sound level meter system. However, environmental factors like phone case, position, and windscreen affected accuracy.
According to audio equipment manufacturer Cirrus Research, differences of up to 10 dB have been observed between apps and dedicated meters (Cirrus Research, 2021). Phone microphone quality, calibration, and processing algorithms can impact accuracy. Overall, decibel apps can provide ballpark figures but professional equipment is needed for legal compliance and precise monitoring.
Uses and Benefits of Phone Decibel Meters
Phone decibel meters have become quite useful for monitoring noise exposure and hearing health. By using decibel meter apps, people can easily measure sound levels in different environments to understand what decibel levels they are being exposed to on a regular basis. This can help prevent noise-induced hearing loss by identifying loud environments that can potentially damage hearing over time. According to the CDC, noise above 70 dB over a prolonged period of time can damage hearing.
Decibel meter apps are especially useful in occupational and industrial settings where workers are exposed to loud machinery and other equipment on a daily basis. Regular sound level monitoring can help employers ensure they are complying with occupational noise exposure regulations and keeping sound levels within safe limits for their employees. OSHA has occupational noise exposure limits of 90 dB for 8 hours per day to protect against hearing damage.
In summary, the key benefits of phone decibel meters include:
- Monitoring personal noise exposure and hearing health
- Measuring sound levels in various environments
- Occupational/industrial safety monitoring
- Ensuring compliance with noise regulations
- Preventing noise-induced hearing loss
By providing easy access to sound level measurements, decibel meter apps empower people to understand noise in their environment and take steps to protect their hearing if needed.
Limitations
While phone decibel meter apps can provide general sound level readings, they have some important limitations to consider:
Phone microphones vary widely in quality and sensitivity. Microphone sensors in smartphones are generally not designed for accurate acoustic measurement, so they may not capture the full frequency spectrum evenly. This leads to inconsistent results across devices (Measuring Sound – is an App as Good as a Sound Level Meter?).
Proper calibration is difficult with phone microphones. Professional sound level meters are individually calibrated to ensure accuracy. Phone microphone calibration is inconsistent and can drift over time as the microphone wears out (How Accurate Are These Smartphone Sound Measurement Apps?).
Environmental conditions impact readings. Factors like temperature, humidity, and placement of the phone matter greatly. Maintaining consistent testing conditions is challenging with phone meters compared to dedicated equipment (So How Accurate Are These Smartphone Sound Measurement Apps?).
Overall, while phone decibel apps can provide ballpark figures, their readings have significant limitations compared to calibrated, professional-grade sound level meters.
Tips for accurate readings
While smartphone decibel meters can provide reasonably accurate readings, there are some tips to follow for getting the most precise measurements:
Use an external microphone: The built-in microphone on smartphones are not calibrated and optimized for accurate sound level measurements. Using an external calibrated microphone connected to the phone’s headphone jack or lightning port can improve accuracy (Source: https://www.soundly.com/blog/best-decibel-meter-apps).
Calibrate your phone: Some decibel meter apps provide a calibration function using an external sound source of a known decibel level. This can help align your phone’s measurements with a true decibel reading. Follow the app’s instructions for proper calibration (Source: https://victorianhearing.com.au/the-best-smartphone-decibel-meter-apps-to-measure-noise-levels/).
Use consistent measurement technique: Small differences in microphone placement and environment can affect readings. Use the same orientation and distance from the sound source each time for consistency. Avoid covering the microphone or holding it differently (Source: https://www.healthyhearing.com/report/47805-The-best-phone-apps-to-measure-noise-levels).
Avoid interference: Other nearby sounds, echo, reverberation, and wind can influence measurements. Take readings in a quiet environment without background noise or air currents (Source: https://www.soundly.com/blog/best-decibel-meter-apps).
Top decibel meter apps
When looking for a decibel meter app, it’s best to choose a popular app with consistently good reviews. The top options provide accurate readings, intuitive interfaces, and useful noise analysis features.
For iOS, some of the best options include SPLnFFT Noise Meter, Decibel 10th, and Too Noisy Pro. SPLnFFT stands out with its detailed analysis capabilities, charting, and data exporting. Decibel 10th is known for its simplicity and accurate readings. Too Noisy Pro provides a color-coded noise monitor and handy calibration tools.
On Android, top choices are Sound Meter, Decibel X, and NoNoise. Sound Meter has a 4.5 star rating and offers detailed noise graphs. Decibel X is popular for its clean interface and spectrum analysis features. NoNoise provides a history graph and background noise filtering for accuracy.
Key aspects to compare are the measurement range, analysis tools, ease of use, and extra capabilities like calibration and data sharing. Checking reviews can help narrow down the best apps for your specific noise measuring needs.
Interpreting and Using Readings
When interpreting decibel readings from phone decibel meters, it’s important to understand safe levels of noise exposure. The CDC notes that noise above 70 dB over prolonged periods can damage hearing over time. At 120 dB and above, immediate harm can occur.
The Hearing Health Foundation provides a guide to decibel levels and potential hearing damage:
– Under 30 dB – Very quiet
– 30 to 60 dB – Normal conversation
– 60 to 90 dB – Sounds can be potentially damaging over time
– 90 to 110 dB – Sounds can cause permanent hearing loss
– 120 to 140 dB – Physical pain may occur
– Above 140 dB – Noise causes immediate damage
Based on these guidelines, if your phone decibel meter records sounds from 90-110 dB, hearing protection like earplugs should be worn to prevent permanent damage. Over 120 dB requires immediate removal from the environment to avoid harm.
It’s important to use decibel meter apps to identify loud environments and take appropriate action. Move away from loud noise sources when possible and wear hearing protection when needed. Monitoring sound levels allows you to be proactive about preventing hearing damage.
Regulatory standards
There are a few key regulations and standards that relate to the use of phone decibel meter apps:
The Occupational Safety and Health Administration (OSHA) has regulations on permissible noise exposure levels in the workplace. OSHA requires employers to implement a hearing conservation program when noise exposure equals or exceeds an 8-hour time-weighted average (TWA) of 85 decibels (dB). Monitoring must be conducted when noise levels are at or above this level to determine employee exposure. See the full details at the OSHA website (OSHA Noise Monitoring Regulations).
The National Institute for Occupational Safety and Health (NIOSH) has developed a sound level meter app that can be used to measure workplace noise exposure. This app conforms to the applicable international standard for sound level meters, IEC 61672-1. See more details in the NIOSH Sound Level Meter App user manual (NIOSH Sound Level Meter App).
For consumer use, there are no specific regulations or standards governing phone decibel meter apps. However, it’s important to verify the accuracy of any app against a certified sound level meter before relying on it for critical measurements.
The future of phone decibel meters
As smartphone technology continues to advance, the future looks promising for phone-based decibel meters. One key area of progress is in microphone quality and audio processing capabilities. Smartphone manufacturers like Apple and Samsung have been steadily improving the microphones built into their devices to support new features like spatial audio and computational photography. These more advanced microphones can capture a wider dynamic range and frequency response, which improves the accuracy of decibel measurements (1).
In addition, faster processors and dedicated audio chips allow more sophisticated audio processing and analysis to happen right on the device. This enables decibel meter apps to implement more advanced calibration and tuning algorithms to further refine their readings (2). For example, Apple introduced on-device ambient noise cancellation in iOS 16 to filter out background sounds before analyzing audio input (3).
Looking ahead, we may see decibel meter apps that can automatically recognize different environmental noise profiles and calibrate accordingly. New augmented reality capabilities could overlay decibel readings directly into the physical environment in real-time. Overall, as smartphone hardware and software evolves, so too will the accuracy and capabilities of phone-based decibel meters.
(1) https://canadianaudiologist.ca/feature-4/
(2) https://www.reddit.com/r/livesound/comments/16x5kf0/are_decible_meter_apps_accurate/
(3) https://www.apple.com/ios/ios-16/