Configured in Settings → Sound.

Audio output

This preference controls how the audio is played. On most systems it affects how the autio is routed (e.g., phone speaker vs headphones vs Android Auto, etc). However, some vendors may add their own "features" breaking the default Android's behavior. Currently, there are three options:

  • Default - Audio is played as a media stream (e.g., Android treats it similar to a music player). In most cases it will be routed through a default device. When Android Auto is connected, in most cases the sound goes through the car speakers. If a Bluetooth device is connected, then the audio goes through Bluetooth.
  • Phone speaker - Highly experimental. Same as "Default", but the app explicitely asks the OS to play the sound through a phone speaker. However, not every phone respects this request, and on some devices the behavior can be quite glitchy (e.g., audio jumping back and forth between the phone speaker and the Android Auto). This mode can be useful when a car stereo has a noticeable sound lag, to expedite the audible alerts delivery.
  • Alarm - Audio is played like an alarm. On most Android devices this means playing through all available devices at the same time (e.g. Bluetooth headset + phone speaker together). However, some vendors add a special treatment to alarm sounds. For example, some Motorola devices, force gradual ramp up to all alarm sounds.

Reset System Volume On Service Start

This configuration allows setting device volume to a specified value whenever the service is started – for example, make it as loud as it can get. Resetting the system volume on start can prevent the alert not being heard due to the low system volume set in the past. Please note that the volume isn't returned to the original value when the service is stopped.

Vocie Announcements Sound

This section allows to configure the volume and the speech rate of voice announcements. On some devices an application restart might be needed for this preference to take effect.

Volume Level

This preference controls the volume of voice announcements. The volume is set in a range from 5 to 100 percent.

Speech Rate

This preference controls the speed of voice announcements. The rate is set in a range from 0.5 to 3.0, where 1.0 is the default speed.

Volume Normalization

This preference controls the volume normalization of the audio alerts. The voice message is produced by a device's TTS engine, and on some devices the volume of the voice message can be significantly lower than the volume of the alert sound. This preference allows to normalize the volume of the voice message to the volume of the alert sound. The volume normalization is applied to the voice message only, the alert sounds are not affected. There are three possible options for voice normalization:

  • None - No normalization is applied, the voice message is played unchanged as it is produced by the TTS engine.
  • Basic - The whole message is normalized according to the EBU R128 standard. The normalization is applied to the whole message, so the volume of the voice message is adjusted to the volume of the loudest part of the message. This is the best options for most cases.
  • Aggressive - Some devices (usually cheaper ones, with a poorly implemented TTS engine) can produce voice messages with varying volume levels thoughout the message. The aggressive mode targets these devices and normalizes the volume of each phoneme independently. This option can make the voice message sound more consistent, but can also slightly distort it and make it sound robotic.