Apple自動調整音量的技術

我們在接、打電話時，電話的音量都是固定的，如果電話離太遠就聽不清楚，否則就要用人工去調整音量大小。從USPTO所公告的專利資料顯示：Apple正在研發一種可自動調整音量的技術，它利用iPhone內置感測器偵測設備到人耳的距離自動調節音量，或是在聽筒和揚聲器之間進行切換，以達到最佳的效果。
當iPhone靠近人的耳時，聽筒音量自動減小；反之自動增大。當用戶放下手機並將手機拿遠時，音訊輸出就會從聽筒轉到外放揚聲器，並且，外放揚聲器音量也會根據iPhone與使用者之間的距離自動進行調節。

US8,452,020
Title : Adjustment of acoustic properties based on proximity detection
Filing Date : 2008.8.20.
Issue Date : 2013.5.28.
Abstract :
One or more acoustic transducers of a device may be adjusted based on automatic detection of device proximity to the user. In a mobile telephone, when the user is using the receiver and holding the telephone against his/her ear, if the telephone detects that the user has moved the telephone further from his/her ear, the telephone will raise the receiver volume. Similarly, if the user is using the speaker, the telephone will adjust the speaker volume as user distance from the telephone changes. In another embodiment the telephone may fade between the receiver and the speaker. Volume is not the only acoustic property that could be adjusted according to user proximity. Frequency response is another property that could be adjusted, such as using appropriate electronic filtering, or by turning on another transducer that is not otherwise being used.