Technical information

Device support

Apple Devices - iOS 15 or newer

Android 9 (Pie) or newer

Overview

The Noise App is a tool designed for users to record noise nuisances on their Apple or Android smartphone or device. The app utilises the device microphone(s) to record a sample of the ‘noise nuisance’ of up to 60 seconds.* App users can make several recordings, which can be associated with the same noise source or different sources. The reporting organisation can set a daily limit of recordings that can be submitted by the app users.The Noise App provides a very efficient means of taking good-quality recordings of noise issues such as animal nuisance, loud music, parties, anti-social behaviour and more. This empowers those affected by noise to gather evidence that can then be accessed by their housing provider. These can be those working within local authorities, housing associations, the police etc.*The maximum limit of recording length is up to 60 seconds depending on the reporting organisation and their subscription.

Microphones

Almost all smartphone manufacturers use microelectromechanical systems (MEMS) microphones in their devices. MEMS microphones typically have a sensitivity between 5 and 17.8 mV/Pa and can capture signals as low as 30 dB SPL and as high as 120 to 130 dB SPL (signal-to-noise ratio >60 dB). MEMS microphones have a flat frequency response similar to ceramic and condenser microphones used in type 2 noise dosimeters. There are limitations with the recording quality of low-frequency noise (<200 Hertz) and noise of a very low level (<25 dB(A)).

Apple and Android device settings

Filters and other noise suppression or cancellation settings have been disabled to ensure that the audio recorded is as representative as possible and of sufficient quality to highlight noise disturbances.Android phones are manufactured by several different suppliers and will vary in the quality of microphone(s) fitted. As a rough indicator of quality, cheaper handsets generally have poorer-quality microphone(s).

Accuracy of recording location

The Noise App captures GPS coordinates each time a user creates a new report. The app will request permission to capture a GPS location as soon as the record button is released on the record screen. Once the location has been captured, the app will stop taking any further readings for the current report.

The app will determine accuracy by two factors:

How recent the GPS location timestamp is (as reported by iOS and Android)
The radius position accuracy GPS parameter in metres (as reported by iOS and Android)

There will be situations where the timestamp is accurate, but the position accuracy is showing a large radius. This can occur when there are insufficient reference points to collect accurate coordinates from, for example:

Poor WIFI
A low quality GPS chipset in device
Poor mobile coverage
Poor signal to a satellite (e.g. sky blockage or atmospheric conditions)

GPS accuracy is usually to within 8 metre radiuses in outdoor conditions. Given that many of our users will be indoors at the time of submission, it is unlikely that devices will produce these figures for each report.

Location services

Location services are required by the app to ensure that the GPS coordinates for the report are captured at the point of recording the audio. In addition to this, if the user opts to set the report location by a map pin (as opposed to an address location), then the location services are used to pinpoint the location of the user.

Security

The Noise App is delivered through secure UK and EU Data Protection compliant infrastructure to ensure personal data is kept confidential. The infrastructure deployed is ISO/IEC 27001 information security canagement compliant and backed up with data protection protocols to ensure data remains secure.