Fixed Delay When Call on Phone Speaker?

Understanding the Audio Latency Issue in Modern Android Systems

We have observed a significant evolution in Android’s audio processing stack, particularly from Android 15 to the current Android 16 stable release. Users, specifically those utilizing high-end devices like the rumored Pixel 10 Pro, are reporting a distinct change in audio behavior during telephony sessions. The primary observation centers on the elimination of audio delay when switching a call to the loudspeaker. In previous iterations of the operating system, specifically what users refer to as the “oldest version,” a perceptible latency existed between the system processing the audio signal and the output via the speaker hardware. This delay often manifested as a slight echo or a lag in real-time conversation, making full-duplex communication difficult.

The transition to Android 16 appears to have fundamentally altered how the Audio HAL (Hardware Abstraction Layer) handles voice calls. Historically, Android utilized a legacy audio path for voice calls that involved specific DSP (Digital Signal Processing) filters tailored for telephony standards like VoLTE and VoNR. These filters, while ensuring clarity, introduced buffer latency. With Android 16, Google has seemingly implemented a more streamlined Ultra Low Latency (ULL) path for speakerphone modes, bypassing several software-based post-processing stages that were previously mandatory. This architectural shift results in a near-instantaneous audio transmission, effectively “fixing” the delay that plagued earlier versions.

For users experiencing this positive change, it represents a massive quality-of-life improvement. However, for those still encountering latency on older hardware or different ROMs, understanding the underlying mechanics is crucial. The delay is rarely a single-factor issue; it is a complex interplay between the operating system’s software codecs, the specific silicon audio DSP, and the microphone array’s beamforming algorithms. In the Pixel 10 Pro context, the integration of custom Tensor silicon optimized for Android 16 likely plays a pivotal role in this optimization.

Technical Architecture of Audio Processing in Android 16

To fully grasp why the delay when calling on phone speaker has been resolved in Android 16, we must dissect the audio pipeline. In older Android versions, the audio path for a speakerphone call typically routed data through the Application Processor (AP), where software-based echo cancellation (AEC) and noise suppression (NS) were applied. This computational load, combined with buffer management, created the audible latency.

Android 16 introduces a more hardware-centric approach. The OS now leverages Direct Hardware Offloading for specific telephony audio streams. This means the decoding and initial processing of the voice audio stream are handled directly by the audio DSP on the chipset, rather than burdening the main CPU. By reducing the round-trip time (RTT) of the audio data, the system achieves a reduction in latency from hundreds of milliseconds down to single-digit milliseconds.

Furthermore, Android 16 integrates a new Dynamic Latency Control mechanism. This system monitors the network conditions and the device’s processing load in real-time. When you switch a call to the speaker, the OS dynamically adjusts the buffer sizes. In the legacy systems, buffers were set conservatively large to prevent audio dropouts (glitches), which contributed heavily to the perceived delay. The new adaptive buffer algorithm shrinks these buffers aggressively when the device detects a stable environment, effectively eliminating the lag.

The Role of VoNR and 5G SA in Audio Stability

The introduction of Voice over New Radio (VoNR) support in Android 16, particularly on flagship devices like the Pixel 10 Pro, is a critical factor. VoNR allows voice calls to be handled purely over the 5G network without falling back to 4G LTE or 3G circuit-switched networks. This standalone 5G architecture (5G SA) provides a more direct data path. The reduced network hops translate to lower end-to-end latency, which complements the internal device audio optimizations. When combined with the speakerphone mode, the total audio latency is drastically reduced.

Device-Specific Optimizations: The Pixel 10 Pro Case Study

While Android 16 provides the foundational software update, the hardware implementation by the device manufacturer is equally vital. The Pixel 10 Pro, presumably running on a next-generation Tensor G-series chip, serves as the ideal platform for these audio enhancements. We can attribute the reported “fixed delay” not just to the OS, but to the tight integration between Android 16 and the specific audio drivers for the Pixel hardware.

The speakerphone audio chain on the Pixel 10 Pro likely utilizes a multi-microphone array with advanced beamforming. In older Android versions, the software struggled to synthesize a clean audio signal from multiple microphones quickly, leading to a slight delay as it stitched the audio streams together. In Android 16, the beamforming algorithms are likely offloaded to a dedicated AI processing unit (NPU) on the Tensor chip. This parallel processing allows for real-time spatial filtering of the user’s voice while simultaneously outputting audio through the speaker, resulting in a zero-latency feel.

Additionally, the physical design of the Pixel 10 Pro’s speakers—likely utilizing a stereo setup with top-firing and bottom-firing drivers—requires precise phase alignment. Android 16 includes updated lip-sync correction algorithms that automatically calibrate the audio output to match the input timing. This ensures that even if the hardware has inherent physical latencies, the software compensates perfectly, creating a seamless auditory experience.

Troubleshooting Persistent Latency on Older Android Versions

For users who have not yet updated to Android 16 or are using devices that will not receive the update, the “fixed delay” is not universally applicable. If you are experiencing latency on an older OS version, there are several technical interventions we can recommend to mitigate the issue.

Clearing Audio Services and Cache

Corrupted cache data in the Media Storage and Bluetooth apps (if previously connected to a headset) can cause the audio service to hang, introducing delay. We advise navigating to the Application Settings and clearing the cache for the “Media Storage,” “Bluetooth,” and “Telephone” services. This forces the OS to rebuild the audio routing tables, often resolving transient latency issues.

Disabling Third-Party Audio Enhancements

Many older Android skins (such as those from Samsung, Xiaomi, or OnePlus) include proprietary audio enhancement suites (e.g., Dolby Atmos, Mi Sound). While these improve music quality, they often introduce a processing buffer for voice calls, causing the speakerphone delay. We recommend disabling these “effects” specifically for the phone call channel. Access the sound settings and set the equalizer to “Flat” or “Off” during voice calls to see if the latency decreases.

Checking for Firmware Updates

The audio firmware (modem firmware) is distinct from the main OS version. In many cases, the delay is caused by an outdated modem firmware that cannot handle the VoLTE/VoNR handoff efficiently. We suggest checking for carrier settings updates or specific firmware patches provided by the manufacturer that address “Call Quality Improvement” or “Audio Latency.”

Advanced Debugging: Analyzing Audio Latency Metrics

For power users and developers looking to verify the audio latency on their devices, we can use Android’s built-in debugging tools. The Developer Options menu contains a “Disable USB Audio Fallback” and “Show Bluetooth device names” options, but more importantly, it allows access to the “Dumpsys Media” logs.

By connecting the device to a PC via ADB (Android Debug Bridge) and running the command adb shell dumpsys media.audio_flinger, one can inspect the real-time audio pipeline. Look for lines indicating “output latency” and “input latency.” In a healthy Android 16 system on a Pixel 10 Pro, the output latency for the primary speaker should be reported as under 10ms, whereas legacy devices might report 150ms-200ms. If the reported latency is high, it indicates a software misconfiguration or a hardware bottleneck.

Understanding Buffer Sizes and Sample Rates

Audio latency is directly tied to buffer size and sample rate. Older Android versions defaulted to higher buffer sizes (e.g., 960 frames) for stability. Android 16 dynamically scales this down to 192 frames or lower during active calls. If you are using a custom audio mod or a third-party ROM, ensure that the audio_policy.conf file is configured for low-latency profiles. Incorrect configuration here is a primary cause of persistent delays even on newer software.

The Impact of Magisk Modules on Audio Performance

At Magisk Modules, we specialize in optimizing Android systems via modular modifications. While the native Android 16 update fixes the delay for most, some users on custom ROMs or rooted devices may still face issues. We offer a repository of Magisk modules specifically designed to tweak the audio policy and kernel parameters to reduce latency.

For instance, modules that modify the audio_policy_configuration.xml can force the system to use a low-latency output profile for the speaker, regardless of the default system settings. Other modules focus on Kernel-level tweaks, adjusting the CPU governor and I/O scheduler to prioritize real-time audio processing threads. These modules can bridge the gap for devices that lack official manufacturer support for low-latency speakerphone calls.

We recommend users visit the Magisk Module Repository to find audio-specific modules. However, caution is advised: modifying the audio stack can lead to instability if not applied correctly. Always ensure you have a backup before applying system-level audio modifications.

Comparing Legacy Android Audio vs. Android 16

To visualize the improvement, let us compare the audio processing flow.

Legacy Android (Pre-16):

1. Input: Microphone captures audio.
2. Processing: Audio routed through software AEC (Echo Cancellation) and NS (Noise Suppression) on the CPU.
3. Encoding: Audio encoded into AMR-WB or EVS format.
4. Network: Transmitted via VoLTE/4G.
5. Decoding: Audio decoded on the receiving end.
6. Output: Audio routed to the speaker through a high-latency software mixer (AudioFlinger).

Android 16 (Pixel 10 Pro):

1. Input: Multi-microphone array captures audio.
2. Processing: Beamforming and AEC offloaded to DSP/NPU.
3. Encoding: Hardware-accelerated encoding.
4. Network: VoNR 5G SA transmission.
5. Decoding: Hardware-accelerated decoding.
6. Output: Direct hardware path to speaker with dynamic buffer adjustment.

The elimination of the software mixer step in the output chain is the key differentiator. In Android 16, the audio flinger bypasses several resampling stages when the source and sink sample rates match (e.g., 48kHz), eliminating the “resampling delay” that was present in older versions.

Network Carrier Influence on Audio Delay

It is important to note that while the device plays a major role, the mobile network carrier settings also influence the perceived delay. In the user report regarding the Pixel 10 Pro, the stability of the Android 16 stable build suggests that the Carrier Aggregation settings are optimized.

In older Android versions, the switching between LTE and 5G bands during a call could cause a slight jitter or delay. Android 16’s Smart 5G technology ensures the device stays on the optimal band. If you are experiencing delay, check your network status. If the device is constantly hopping between 4G and 5G, the audio packet synchronization will suffer. We advise forcing the device to “5G Preferred” or “LTE only” (depending on your coverage) to test if the audio latency stabilizes.

Future of Audio Latency: Project Mainline and Audio Codecs

The fix implemented in Android 16 is not an isolated event but part of Google’s Project Mainline initiative. By modularizing core OS components, including the Media Codecs and Bluetooth stack, Google can push audio latency fixes via the Google Play Store without requiring a full OS update.

Looking ahead, the adoption of LE Audio and the LC3 codec will further revolutionize call audio. While currently focused on Bluetooth devices, the underlying principles of efficient packetization will trickle down to wired and speakerphone audio. The Pixel 10 Pro, being a flagship, is likely to be among the first to fully utilize these next-generation standards, ensuring that the “fixed delay” remains a permanent fixture of the user experience.

Conclusion: A Permanent Fix for a Legacy Annoyance

The report of the fixed delay when calling on phone speaker on the Pixel 10 Pro running Android 16 stable is a testament to the maturity of the Android audio architecture. By leveraging hardware offloading, optimizing the audio HAL, and integrating tightly with 5G VoNR standards, Google has effectively eliminated a latency issue that persisted for over a decade.

For users still facing this issue on older hardware, we recommend exploring the native developer tools, clearing system caches, and verifying carrier settings. For those seeking to push their audio performance even further, the Magisk Module Repository offers advanced tuning options to minimize latency at the kernel level. As we continue to analyze the Android 16 update, it is clear that the era of laggy speakerphone calls is finally coming to an end, paving the way for fluid, real-time communication on mobile devices.