16, 24 or 48 kHz: why your hearing aids can't hear some Auracast broadcasts

You set up an Auracast transmitter on the TV. Your partner's earbuds join straight away. Your hearing aids see the broadcast in the app, but nothing plays, or they won't select it at all. The usual cause is the sample rate.

Two quality tiers

Every Auracast broadcast uses the LC3 codec, but LC3 can run at different sample rates. The Bluetooth SIG groups them into two tiers:

• Standard Quality: 16 kHz or 24 kHz. Aimed at speech, with smaller packets that the SIG says give slightly better range.
• High Quality: 48 kHz. Intended for music.

The tiers are defined in the Public Broadcast Profile (PBP), the part of the Bluetooth spec that lets a broadcast advertise what it carries. Standard Quality is built from the configurations that every Bluetooth broadcast receiver is required to decode. High Quality is a list of 48 kHz configurations that, in the SIG's words, receivers are "not mandated" to support in either the Basic Audio Profile or PBP.

So a receiver can be fully compliant and still be unable to play a 48 kHz broadcast. The SIG's transmitter guide names the usual suspects: "some resource-constrained devices, such as hearing aids, may only be capable of receiving" Standard Quality streams. Hearing aids run on tiny batteries, and decoding a 48 kHz stream costs power.

What the rules actually say

This is where it gets misquoted, so it's worth being precise.

The PBP specification itself does not force a transmitter to send Standard Quality. It defines the two tiers and gives a broadcast a way to flag which ones it carries. The firmer rules come from the SIG's Auracast transmitter best-practice guide (version 3, October 2025), which says:

• All Auracast transmitters "are required to be able to transmit" at 16 or 24 kHz.
• A personal transmitter, such as a TV box, may default to High Quality, but must let the user choose Standard Quality. The maker decides whether it sends both at once or one instead of the other.
• A product marketed for public locations must default to Standard Quality.
• A venue that promotes Auracast is "required to make available a Standard Quality version of any audio" it broadcasts.

In short: 48 kHz is allowed, Standard Quality is the baseline, and public venues are expected to provide it.

What venues should do

Run Standard Quality on every programme. If you also want a 48 kHz stream for music, run it alongside, not instead. The SIG's guide treats "both 24kHz and 48kHz audio streams being simultaneously transmitted" as a normal arrangement, and recommends that alternative versions sit in separate subgroups so a phone can list them as separate choices.

Venue hardware is built for this. The Auri TX2N, the transmitter behind the Sydney Opera House installation, has two radios, and each stream has its own sample rate and input routing, so on paper one input can go out at 24 kHz on one stream and 48 kHz on the other. Name them clearly ("Concert Hall" and "Concert Hall HQ", say) so listeners know which to pick. There is more in our venue guide.

How to tell, and how to fix it at home

If hearing aids can see a broadcast but won't play it, check the transmitter's quality setting first.

• LG TVs with built-in Auracast let you pick 16, 24 or 48 kHz in the Sound menu. Choose 24 kHz.
• Avantree's Audikast 4 and 4HA have a separate Hearing Aid Mode. Avantree's guides say hearing aids "cannot join unless the mode light is solid white"; holding the right-hand Auracast button switches between white (hearing aids) and orange (other Auracast devices). Avantree doesn't publish the sample rate behind each mode, but a HearingTracker tester found the Audikast 4 cannot send 24 kHz and 48 kHz at the same time: you choose one.
• The MOER TV hearMore needed a firmware update and its PC tool set to 24 kHz before one owner's Jabra aids would join.

We haven't found a consumer TV transmitter that its maker says sends Standard and High Quality at once. Until one appears, a home with hearing aids should leave the transmitter on 24 kHz. Every compliant receiver is meant to decode it, though see below.

The mirror case: earbuds that only like 48 kHz

Most earbuds play anything. Not all. Owners of the EarFun Air Pro 4 report on EarFun's forum that, on the unofficial Auracast firmware, 48 kHz broadcasts work but 24 kHz ones make the earbuds disconnect and reconnect. A second owner confirmed the same on firmware 1.2.8 in April 2026, and noted that their church broadcasts at 24 kHz. EarFun has not responded or published release notes, which is why we list the Air Pro 4 as pending.

That's backwards from the spec: 24 kHz is one of the configurations every receiver is meant to decode. It also means a household with both the Air Pro 4 and hearing aids can't share a single-rate transmitter until EarFun fixes it.

The short version

• Hearing aids that won't play a broadcast: set the transmitter to 24 kHz or its hearing-aid mode.
• Running a venue: always broadcast Standard Quality; add 48 kHz as a second stream if you want it.
• Buying earbuds: check the product page for reports of 24 kHz trouble before you rely on them at a venue.