Implementing Acoustic Echo Cancellation Tuning for Open-Plan Office Environments

How-To-Articles
1

Implementing Acoustic Echo Cancellation Tuning for Open-Plan Office Environments

What This Guide Covers

This guide details the architectural configuration required to enable high-fidelity Acoustic Echo Cancellation (AEC) within Genesys Cloud CX environments specifically designed for open-plan office settings. The end result is a standardized audio policy that enforces endpoint hardware capable of active noise control and configures platform-side DSP parameters to minimize far-end echo during high ambient noise conditions.

Prerequisites, Roles & Licensing

To implement the configurations described below, the following prerequisites must be met within your tenant environment:

Licensing Tiers:

  • Genesys Cloud CX Premium or Enterprise: Basic tiers may lack granular control over audio quality metrics required for AEC monitoring.
  • WEM Add-on Required: Access to Audio Quality reporting and Endpoint Policy management requires the Workforce Engagement Management add-on.

Granular Permissions:

  • Audio > Audio Quality > Read (To monitor echo levels)
  • Endpoint > Policies > Edit (To enforce headset standards)
  • Telephony > Trunk > Edit (To manage codec negotiation priorities)
  • User > Settings > Edit (To assign specific endpoint configurations to user groups)

External Dependencies:

  • Certified USB Headsets: Devices must support hardware-level AEC (e.g., Jabra, Poly, Plantronics models certified for Genesys Cloud). Bluetooth headsets are explicitly excluded from this configuration due to variable DSP implementation.
  • Network QoS: The network infrastructure must prioritize SIP/RTP traffic with DSCP values marked as EF (Expedited Forwarding) to ensure low jitter, which is critical for AEC algorithm stability.

OAuth Scopes (for API-driven provisioning):

  • audioquality:read
  • endpointpolicy:write
  • users:read

The Implementation Deep-Dive

1. Enforcing Endpoint Hardware Standards via Endpoint Policies

The foundation of effective Acoustic Echo Cancellation is the hardware itself. In open-plan environments, software-based echo cancellation often fails if the microphone array cannot distinguish between agent speech and ambient noise. You must enforce the use of USB headsets with dedicated DSP chips rather than relying on laptop microphones or generic Bluetooth devices.

Configuration Steps:

  1. Navigate to Admin > Endpoint Policies within the Genesys Cloud Admin UI.
  2. Create a new policy named OpenPlan_Audio_Standard.
  3. Under the Endpoint Type section, select Softphone or WebRTC as the primary supported type for agents operating in open zones.
  4. Configure the Hardware Restrictions to whitelist specific USB headset model IDs.
  5. Set the Audio Quality Thresholds to trigger warnings if the device falls below a MOS (Mean Opinion Score) of 3.5.

The Trap:
A common misconfiguration occurs when administrators allow “Auto-Select” for endpoint types without enforcing hardware constraints. If an agent connects via a Bluetooth headset in an open plan, the Bluetooth audio protocol introduces latency and compression artifacts that break the adaptive filter used by AEC algorithms. This results in the “robot voice” effect or persistent echo loops where the agent hears their own voice delayed by 100ms to 500ms. This degradation is catastrophic for customer experience and agent cognitive load. Always enforce USB connection standards via policy rather than relying on user preference.

Architectural Reasoning:
By locking the endpoint policy to USB devices with known DSP capabilities, you offload the echo cancellation processing from the CPU to a dedicated hardware chip within the headset. This reduces CPU utilization on the agent machine, ensuring that network jitter buffers can be tuned more aggressively without risking processor overload during peak call volumes.

2. Codec Negotiation and Bandwidth Allocation

Codec selection directly impacts the ability of the AEC algorithm to function. Lower bandwidth codecs like G.729 compress audio heavily to save bandwidth, but this compression removes spectral data that the echo cancellation algorithm relies on to identify the echo path. In open-plan environments where signal-to-noise ratios are poor, you must prioritize higher fidelity codecs to give the DSP more information to work with.

Configuration Steps:

  1. Access Admin > Telephony > Trunk Groups.
  2. Edit the trunk group assigned to your contact center users.
  3. Modify the Supported Codecs list. Ensure PCMU (G.711u) is listed first, followed by PCMA (G.711a).
  4. Set the Bandwidth Configuration to allow a minimum of 128kbps for audio traffic per direction.
  5. Disable low-bandwidth codecs such as G.729 or Opus in narrowband modes for this specific policy group.

The Trap:
The most frequent failure mode here is enabling G.729 to save on bandwidth costs during a network audit. While G.729 reduces bandwidth consumption by 50%, it introduces quantization noise that mimics acoustic echo. The AEC algorithm interprets this compression noise as far-end echo and attempts to cancel it, resulting in the cancellation of legitimate speech components. This creates the “underwater” audio effect where voices sound muffled and distorted. In an open-plan setting, this distortion is indistinguishable from background noise, leading agents to speak louder, which further degrades the acoustic environment for colleagues nearby.

Architectural Reasoning:
G.711 codecs transmit raw pulse-code modulation data without significant compression. This preserves the full frequency spectrum required for the Genesys Cloud audio engine to perform robust echo path estimation. While this consumes more bandwidth, the cost is negligible in modern enterprise networks compared to the operational cost of failed calls and reduced agent productivity caused by poor audio quality. The bandwidth requirement should be viewed as a necessary investment in signal integrity.

3. Configuring Noise Suppression and AEC Thresholds

Genesys Cloud provides specific audio quality settings that control how aggressively the system suppresses noise relative to the voice signal. In an open-plan office, the background noise floor is significantly higher than in a cubicle or private office. Standard thresholds designed for quiet environments will cause the system to cut off speech during normal conversation if the ambient noise spikes.

Configuration Steps:

  1. Navigate to Admin > Audio Quality settings.
  2. Locate the Noise Suppression Level configuration.
  3. Adjust the suppression threshold from the default “Standard” to “Aggressive”.
  4. Configure the Echo Cancellation Sensitivity parameter to “High”.
  5. Set up a custom metric alert that triggers if Echo Return Loss Enhancement (ERLE) drops below 20dB for more than 60 seconds.

The Trap:
Administrators often configure Noise Suppression to “Aggressive” without adjusting the voice activity detection (VAD) sensitivity. When an agent speaks normally in a loud environment, the system may interpret parts of their speech as background noise and mute them. This results in choppy audio where words are cut off mid-sentence. The correct approach is to pair Aggressive Noise Suppression with VAD tuning that accounts for the higher ambient noise floor. If you do not adjust the VAD threshold, the agent will experience intermittent muting during high-stress calls, leading to frustration and increased call handling time.

Architectural Reasoning:
Noise suppression and AEC are distinct but interdependent processes. Noise suppression filters out steady-state background sounds (HVAC, keyboard typing), while AEC specifically targets the feedback loop from the speaker back to the microphone. By setting the Echo Cancellation Sensitivity to “High”, you instruct the platform to allocate more processing cycles to analyzing the acoustic path for echoes. This is computationally expensive but necessary when the signal-to-noise ratio is low. The ERLE metric provides a quantitative measure of how much echo is being cancelled; a drop below 20dB indicates the algorithm is struggling to isolate the echo path, requiring immediate hardware or network intervention.

4. Network QoS and Jitter Buffer Configuration

The stability of AEC algorithms is heavily dependent on packet arrival times. In an open-plan office, Wi-Fi congestion is a primary risk factor. If packets arrive out of order or with high jitter, the adaptive filter in the echo canceller cannot converge, rendering it ineffective regardless of headset quality.

Configuration Steps:

  1. Access Admin > Network Configuration settings.
  2. Define QoS policies for the specific subnets where agents operate.
  3. Mark all SIP (5060) and RTP (port range 50,000-60,000) traffic with DSCP EF (46).
  4. Configure the Jitter Buffer on the Genesys Cloud side to use a Dynamic Jitter Buffer rather than a Static one.
  5. Set the Maximum Jitter Buffer Delay to 200ms for voice calls in this policy group.

The Trap:
A critical failure occurs when administrators hard-code a static jitter buffer size (e.g., 100ms) for all users. In an open-plan environment, Wi-Fi interference causes variable latency spikes. A static buffer cannot adapt to these spikes, causing the audio stream to freeze or drop packets. When the buffer freezes, the echo cancellation algorithm loses its reference signal and fails completely. This leads to sudden bursts of loud echo as the system attempts to re-synchronize. Using a Dynamic Jitter Buffer allows the system to expand the buffer during network congestion and contract it when the network is stable, maintaining the continuous data stream required for AEC convergence.

Architectural Reasoning:
The jitter buffer acts as a temporary storage mechanism that smooths out network irregularities before audio reaches the DSP. For AEC to function, the reference signal (what was sent) must match the return signal (what was received) within a precise time window. Network jitter breaks this synchronization. By allowing the system to dynamically adjust the buffer size up to 200ms, you provide a safety margin for network fluctuations without introducing so much latency that conversation feels unnatural. This dynamic adjustment is essential for maintaining AEC performance on unstable wireless networks common in open-plan layouts.

Validation, Edge Cases & Troubleshooting

Edge Case 1: Bluetooth Headset Interference

The Failure Condition: Agents report intermittent echo during calls while using a Bluetooth headset connected to their laptop.
The Root Cause: Bluetooth headsets typically use the HFP (Hands-Free Profile) which operates at lower bandwidths and uses a different DSP implementation than USB devices. The Genesys Cloud platform cannot guarantee AEC performance on HFP connections due to protocol overhead.
The Solution: Implement an automated check using the GET /api/v2/audioquality endpoint to detect the device type. If the device reports as Bluetooth, force the user to switch to a wired USB headset or route them to a softphone configuration that disables Bluetooth audio routing.

Edge Case 2: High Latency in Wi-Fi Roaming

The Failure Condition: Echo is detected only when agents move between different access points within the open-plan floor.
The Root Cause: During roaming, there is a brief period where the client device disconnects and reconnects to the new AP. This causes packet loss that desynchronizes the echo cancellation filter.
The Solution: Ensure 802.11r (Fast BSS Transition) is enabled on the wireless infrastructure. Additionally, configure the Genesys Cloud endpoint policy to require a minimum Wi-Fi signal strength of -65 dBm before allowing call initiation. This prevents agents from attempting calls while roaming or in weak signal zones where packet loss is inevitable.

Edge Case 3: Agent Speaking Over Headset Speaker

The Failure Condition: The system detects high echo levels even with certified headsets installed.
The Root Cause: Agents are using the headset’s “Monitor” or “Sidetone” feature incorrectly, or they have disabled the microphone on the headset and are using the laptop speakers for audio playback while speaking into the laptop mic. This creates a direct acoustic loop that bypasses the digital AEC entirely.
The Solution: Educate agents to ensure the headset microphone is active and the speaker volume is not so high that it feeds back into the mic. Use the Audio Quality dashboard to monitor Mic Input Level. If levels are consistently low, the agent may be speaking too softly, causing the system to increase gain, which amplifies background noise and confuses the AEC algorithm.

Official References