{"schemaVersion":1,"record":{"key":"mechanic/phone-microphone--family-sonar","type":"mechanic","id":"phone-microphone--family-sonar","lang":"en","title":"Speaker and microphone as an acoustic probe","summary":"The phone emits a sound pulse and records its reflection. Return-signal delay is used to estimate obstacle distance.","updatedAt":"2026-10-22","status":"active","url":"https://gamemechanics.pro/en/knowledge/mechanic/phone-microphone--family-sonar/","jsonUrl":"https://gamemechanics.pro/api/v1/knowledge/en/mechanic/phone-microphone--family-sonar.json","markdownUrl":"https://gamemechanics.pro/content/knowledge/en/mechanic/phone-microphone--family-sonar.md","aliases":["Speaker and microphone as a probe"],"tags":["Phone microphone interactions","Mechanics catalog"],"sourceIds":["source-b0f0f5dae74bfce2","source-3cd3d0111315b387","source-2a4797d398583c78"],"sources":[{"id":"source-b0f0f5dae74bfce2","title":"FingerIO: active sonar for finger movement","url":"https://homes.cs.washington.edu/~gshyam/Papers/fingerio.pdf","verifiedAt":null},{"id":"source-3cd3d0111315b387","title":"CMU/Disney: Acoustruments","url":"https://www.cmu.edu/news/stories/archives/2015/april/acoustruments-for-handheld-devices.html","verifiedAt":null},{"id":"source-2a4797d398583c78","title":"phyphox","url":"https://www.youtube.com/watch?v=Ebj3v701HE0&t=185s","verifiedAt":null}],"sections":[{"id":"principle","title":"How it works","body":"This is active acoustic sensing. The phone emits a known signal and analyzes the reflection; support, accuracy and audibility require testing."},{"id":"variants","title":"Variants","body":"### Variants and applications\n\n<a id=\"family-sonar-variants\"></a>\n\n- Contactless button. Signal: Change in reflection from a close hand. Application: By waving over the phone, activate the game action. Access level: R. <a id=\"variant-mic-105\"></a>\n- Approaching the palm. Signal: Estimation of changes in distance to the reflector. Application: Control a virtual theremin without touching. Access level: R. <a id=\"variant-mic-106\"></a>\n- Movement to and from the telephone. Signal: Doppler or phase signature. Application: Push and pull a game object with your hand in the air. Access level: R. <a id=\"variant-mic-107\"></a>\n- Finger trajectory. Signal: Echo changes on multiple channels. Application: Draw next to the screen or expand the work area. Access level: R. <a id=\"variant-mic-108\"></a>\n- Circular or side gesture. Signal: Classification of reflector trajectories. Application: Switch pages or cast a circular spell. Access level: R. <a id=\"variant-mic-109\"></a>\n- Changing obstacles. Signal: The difference in reflections of the reference signal. Application: Notice the appearance of an object in a small play area. Access level: R. <a id=\"variant-mic-110\"></a>\n- Acoustic resonator. Signal: Change in response of a prepared object. Application: Assemble musical castles from tubes and cavities. Access level: R. <a id=\"variant-mic-111\"></a>\n- Distance between devices. Signal: Sound travel time, taking into account delays and synchronization. Application: Solve a cooperative problem with the mutual arrangement of telephones. Access level: R. <a id=\"variant-mic-112\"></a>"},{"id":"context","title":"Context and limits","body":"Author's design map for mobile games and interactive applications. 144 techniques in 18 groups, including basic signals, rules and combinations. Applications are design ideas and not a list of released games."}],"relations":[],"placements":[{"catalogId":"phone-microphone","id":"family-sonar","title":"Phone microphone interactions","url":"https://gamemechanics.pro/en/mechanics/phone-microphone/#family-sonar","categoryIds":["section-1"]}],"supersededBy":[],"attributes":{"preview":{"updatedAt":"2026-10-22","title":"Speaker and microphone as a probe","description":"The phone emits a sound pulse and records its reflection. Return-signal delay is used to estimate obstacle distance.","image":{"src":"images/mechanics/sensor-phyphox-sonar-185.webp","width":1280,"height":720,"game":"phyphox","sourceUrl":"https://www.youtube.com/watch?v=Ebj3v701HE0&t=185s","originalUrl":"https://www.youtube.com/watch?v=Ebj3v701HE0","sourceFrameSeconds":185,"credit":"RWTH Aachen University / phyphox","rights":"© RWTH Aachen University / phyphox. Frame from the developers’ sonar demonstration. All rights reserved; excluded from MIT and CC BY 4.0.","caption":"phyphox Sonar: reflected signal on a distance scale","alt":"phyphox Sonar: reflected signal on a distance scale","markers":[{"x":31,"y":47,"label":"The echo peak is mapped to distance in centimeters"}]},"tips":["Check multiple reflections, device latency and the sound speed under experiment conditions."],"examples":[{"title":"phyphox","url":"https://www.youtube.com/watch?v=Ebj3v701HE0&t=185s"}]}},"endsAt":null,"provenance":"Original editorial design catalog consolidated from project discussions on 2026-10-20. Complete discussion item lists and contextual limitations are preserved; linked primary sources support specific techniques, not the entire classification. English translation was prepared with machine assistance and editorial review.","license":"CC-BY-4.0","codeLicense":"MIT","attribution":"gamemechanics.pro contributors","catalogKey":"catalog/phone-microphone"}}