A practical DSP solution for mobile phone stereo sound recording

Alango Stereo Solution With 2 mic

Scheme of Microphones PositionIn Mobile Phone

1 Microphone from the Right Side1 Microphone from the Left Side

Left Field Right Field

Stereo Sensitivity Fields

2

Stereo Technology Diagram 2 mic recording

Right

Left

Left

ADM1Right Channel

Left Channel ADM2

Right

3

Right

Left

Alango processing

Alango 2 microphone system for stereo audio recordingsprovides following benefits:

• True stereo, high quality sound recording• Wind reduction

Alango Stereo Solution With 4 mic

Front side Rear Side

2 front microphones 2 rear microphones

Alango 4 microphone system for stereo audio recordingsprovides following benefits:

• True stereo, high quality sound recording• Attenuation of sounds outside the camera view• Attenuation of user’s voice from the recording• Wind reduction

Scheme of Alango4 microphone system

4

Event Recording

Left Channel Right Channel

Stereo Sensitivity Area

Illustration of Stereo Recording with 4 mic

Sounds from Rear & Side directionsSounds from Rear & Side directions

Right SideLeft Side

Rear Side 5

Stereo Technology Diagram With 4 mic

6

ADM1

ADM2

Right Channel

Left Channel

Right

Left

• Adaptive Directional Microphones (ADM) technology use signals from four omnidirectional microphones and according to phase difference, and programmed parameters system enhances sounds coming from left (left channel) or right (right channel) angular directions.

• Sounds coming from side and rear directions (including user’s voice) are attenuated.

Mobile phone sketch

Our system provides naturalstereo sensation of

incoming sounds

Sounds from Rear& Side directions

Sounds from Rear& Side directions

Recording Environment

Alango processing

Sony stereo microphone

Alango technology with 4 mic

Comparison of Stereo Sound Recordings

Stereo sound recordings from:

Enjoy the listening and feel the difference by pressing the buttons below

7

2 phone mic (left, right), unprocessed

Alango technology with 2 mic

1 song 2 song

Test Setup