您将学到什么：
- Benefits derived from the new Bluetooth LE Audio standards and specs.
- The arrival of Bluetooth broadcast audio.
- A look at how the broadcast streams work.
在过去的20年中，蓝牙无线技术已成为个人音频的标准。从最初在耳机中用于免提移动通话，它涵盖了高质量的音乐流，随着智能手机和流媒体应用程序的可用性的增加而越来越受欢迎。苹果的Airpods的到来以及随后对耳塞的热情导致这成为我们见过的最快的消费产品行业。
Now, the Bluetooth SIG just recently launched its new Bluetooth LE Audio set of standards. It consists of a comprehensive set of specifications designed to support the next 20 years of audio development, allowing the industry to offer even more innovation in both products and applications.
Requirements from the hearing-aid industry prompted Bluetooth LE Audio development. Although separate from the consumer audio market, hearing aids have had to solve many problems that are still challenging for consumer earbuds.
Because they’re worn all day, without the opportunity for recharging, they need to operate on little power. In many cases, users may wear different hearing aids in each ear—something that most current true wireless stereo (TWS) earbuds don’t allow, as they rely on proprietary methods to keep the earbuds synchronized with each other.
最后，助听器支持广播系统，多个佩戴者可以在该系统中与公众连接，感应循环系统被称为电信。
所有这些特性对everyd巨大的使用ay audio use cases, but they had fallen into the “too hard” category. It also was apparent that the existing Bluetooth audio specifications were limiting, with the Hands Free Profile designed predominantly for cellular calls and the A2DP specifications confined to streaming music to a single set of earbuds or headphones.
最近的发展，例如语音助手以及空间音频的出现和增强现实，这清楚地表明，需要更大的灵活性。它促使该行业聚集在一起提供蓝牙LE音频，以支持新一代的音频应用程序。
Updating the Basics
At the heart of the new specifications is the move to use Bluetooth Low Energy, released in 2010 as a much lower power option, intended for devices like wearables and health sensors. It has now extended to support multiple audio streams.
The standard has introduced a new audio codec—the LC3—to make audio even lower power. The LC3 has been optimized to support both voice and music applications, providing the same subjective quality as current audio codecs at around half the bit rate. This means that smaller amounts of information need to be transmitted, lowering the power consumption and reducing the likelihood of interference from other radio sources.
设计师可以使用这种新的灵活性来降低功率并增加电池寿命。另外，它们可以传输多个流以用于空间音频，支持多种语言，或者使用他们获得的额外资源来进行更有效的音频算法，例如消除噪声。
Broadcast Audio: A New User Experience
这些功能改善了当今的无线音频体验，但是真正的游戏规则改变者介绍了广播能力。最简单，这允许发射器将相同的音频流发送到多个设备。自索尼（Sony）的Walkman到来以来，早在1979年，朋友们分享了耳塞来听音乐。使用蓝牙LE音频，您确实可以剪断电缆，使许多人都可以听相同的音频流。
However, this isn’t just about sharing personal music from your phone.
广播音频可用于公开公告，例如旅行信息。这是类似于助听器佩戴者今天使用电感循环电视系统所能体验到的用例。使用蓝牙LE音频，此功能可以扩展到任何LE Audio耳塞或助听器收到的高质量音乐。
这些广播发射机将是低成本且易于安装的。因此，任何场所，例如健身房，酒吧或咖啡店，都可以为其客户提供多个音频流，无论是背景音乐还是提供音频以伴随多台电视。
查找并连接到这些流很简单，不需要配对。这些广播流包括描述其内容的元数据，允许用户选择如果有多个不同的广播公司，他们可以听到什么。
就像手机可以检测Wi-Fi访问点一样，类似的扫描可以提供范围内广播音频流的列表（见图）。单击任何广播源都会将您的耳塞切换为接收所选音频流。音频将直接从广播源到您的耳塞 - 手机仅充当控制器，本质上是遥控器。
广播流也可以进行加密和身份验证，使其成为临时，私人对话的主要内容，例如在售票桌或酒店接待处与某人交谈。这意味着您可能会佩戴更长的耳塞，就像听力援助用户一样；因此，LE音频的较低功耗特别有益。
Because broadcasts are one way, they take advantage of the higher link budget from an infrastructure transmitter to the earbud (the reverse link budget is limited by power constraints and antenna size within an earbud or hearing aid). The range is therefore significantly greater than conventional Bluetooth or Wi-Fi. Hence, a single broadcast transmitter can cover large rooms and venues.
Wide-Ranging Support
新的蓝牙LE规格支持广泛的应用程序。行业支持非常出色，多个硅供应商为发射机（通常是电话，电视和独立广播设备）以及耳塞，耳机和扬声器提供合规的芯片。
基础核心功能是在5.2版本中引入的，这意味着许多设备已经具有硬件能力。尽管在蓝牙LE Audio的情况下，始终需要花费时间到市场上出现的产品和应用程序，但似乎我们将很快看到第一批产品出现。
To provide more detailed information, I’ve just published a book to help explain how the various specifications fit together and present the potential applications. Called “蓝牙LE音频介绍，”现在可以在平装本或亚马逊的精装本中获得。数字版本也是available for download from the Bluetooth SIG website。
