Quiet Calls, Clear Thinking: How Halfalogue disrupts workflow

Understanding the science of “halfalogues” and what employers can do about them.

You’re concentrating on a proposal when a colleague nearby starts a phone call.

You hear: “No, Tuesday won’t work…” “Can you send that through before lunch?” “I’ll check with the client and come back to you.”

You never hear the other person speaking, yet your attention keeps drifting toward the conversation.

That experience is called a halfalogue.

A halfalogue is a conversation where only one side is audible, such as a phone call, Teams call, or video meeting heard from a nearby desk. Research suggests that halfalogues are often more distracting than hearing two people talk face to face, which helps explain why a single desk call can feel disproportionately disruptive in an open-plan office.

For employers trying to improve productivity, focus, and employee wellbeing, this is more than a minor annoyance. It is a measurable workplace performance issue

Why halfalogues are uniquely distracting

One of the most influential studies on this topic was conducted by Lauren Emberson, Michael Lupyan, Edward Goldstein, and Diane Spivey (2010). Participants performed attention-demanding tasks while listening to either a full conversation, a halfalogue,or ambiguous background noise.

The study found that performance was significantly worse when participants heard a halfalogue. Hearing only one side of a conversation made it much harder to ignore the speech and stay focused on the task.

Emberson and colleagues argued that the missing half of the conversation creates an information gap. The brain automatically tries to predict what the unheard speaker is saying, which captures attention even when we are trying to concentrate.

In practical terms, a nearby phone call is not just sound; it is an unresolved puzzle.

Why your brain struggles to tune it out

This effect appears to be deeply rooted in human attention systems.

Research in auditory cognition shows that the brain is highly sensitive to speech because it often carries socially relevant information. Evolutionarily, being able to detect and interpret nearby conversations could provide important cues about safety, cooperation, or threats.

A useful concept here is speech intelligibility. The more understandable speech is, the more likely it is to capture attention. When a conversation is clear enough to follow partially, the brain keeps monitoring it.

Several studies have explored this by using rotated speech; speech that has been acoustically transformed so it retains some sound characteristics of speech but becomes unintelligible. (In simple terms, rotated speech sounds speech-like, but the words can no longer be understood.)  Researchers found that intelligible speech is far more distracting than unintelligible speech, supporting the idea that it is the meaning of the conversation, not just the noise level, that interferes with concentration.

This is why employees often report that a nearby phone call is more distracting than a constant background hum such as air conditioning.

The productivity cost of office phone calls

Later studies led by John E. Marsh and colleagues has consistently shown that background speech impairs performance on tasks requiring reading, memory, and concentration. Their work demonstrates that speech competes for cognitive resources that would otherwise be used for the primary task.

For workplace leaders, the implications are significant:

• More errors in detail-oriented work.

• Slower task completion due to repeated attentional shifts.

• Reduced quality of thinking on complex tasks.

• Higher cognitive fatigue across the day.
  

A halfalogue may last only a few minutes, but the loss of concentration often lasts much longer.

In open-plan offices, these interruptions are multiplied across the entire floor. One employee taking a call can affect many people simultaneously.

The hidden wellbeing cost

The impact is not limited to productivity.

Constant exposure to intelligible speech can increase feelings of mental fatigue and reduce perceived control over the work environment. Employees may begin using headphones continuously, withdrawing from collaborative spaces, or avoiding tasks that require deep concentration.

Over time, this can contribute to a workplace that feels mentally noisy even when the actual decibel level is relatively moderate.

For organisations competing for talent, the ability to provide places for focused work is increasingly part of the employee experience, not just a facilities issue.

What employers can do about it

The research does not suggest banning phone calls. Communication is essential. The goal is to separate call activity from concentration-heavy work where possible.

1. Create dedicated call zones

Encourage phone and video calls to be taken in designated acoustic spaces rather than at open desks.

2. Protect focus areas

Keep some areas of the office primarily for quiet work, reading, writing, and analysis.

3. Schedule concentration time

Use protected focus blocks, particularly on Monday mornings when many employees are tackling high-value work.

4. Reduce speech intelligibility

Acoustic treatment, soft furnishings, and enclosed call spaces help reduce how understandable speech is to surrounding employees.

Why acoustic call pods are effective

This is where workplace design becomes a practical productivity tool.

Enclosed acoustic booths reduce the amount of intelligible speech escaping into the surrounding office while also giving the caller a quieter environment for the conversation itself. For organisations looking for dedicated call and focus spaces, the Hush range offers several options:

• Hushfree XS – a compact single-person booth designed for short phone and video calls. It carries a Class A acoustic rating and provides sound reduction of up to 33 dB.
  

• Hushfree S – a larger enclosed workspace suitable for calls, focused work, and concentration-heavy tasks. It also features a Class A acoustic rating with sound reduction of up to 33 dB.
  

• HushPhone – a more budget-friendly option for routine phone and video calls, offering a Class B acoustic rating with sound reduction of up to 30 dB. View a full breakdown 23351-1:2020 and how acoustic ratings affect the workplace here
  

The important point is not the specification itself; it is the workplace outcome. By moving calls into acoustically controlled spaces, organisations can reduce distraction for surrounding employees while improving privacy and call quality for the caller. For teams dealing with frequent phone and video conversations, even a single dedicated call booth can noticeably reduce the amount of speech-based distraction experienced across an open-plan office. Get ahead Monday. Take it easy Friday. Looking to create a dedicated focus space? Speak with our team about how a Hush acoustic office pod can help reduce distractions and support focused work across your workplace. Research referenced in this article

• Emberson, L. L., Lupyan, G., Goldstein, M. H., & Spivey, M. J. (2010). Overheard Cell-Phone Conversations: When Less Speech Is More Distracting.
  

• Marsh, J. E., et al. (2018). Research on background speech and cognitive performance.
  

• Why Are Background Telephone Conversations Distracting? 
  

• Galván, V. V., et al. (2013). The Effects of Cell Phone Conversations on the Attention and Memory of Bystanders.
  

• Sörqvist, P. (2010). Effects of aircraft noise and speech on prose memory.