Why You Hear What You Expect to Hear

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“‘Scuse me while I kiss this guy.”

For decades, listeners have confidently misheard this lyric from Jimi Hendrix’s Purple Haze, despite the actual line being “’Scuse me while I kiss the sky.” Misheard phrases like this are often called mondegreens, a term coined by writer Sylvia Wright in 1954 after she misheard a line in a Scottish ballad.

Speech Is Messy

Mondegreens are often humorous, but they highlight something fundamental about language: we don’t simply hear speech, we also interpret it.

Interpretation, as it turns out, is deeply shaped by expectation. In everyday conversation, speech is not neatly separated into individual words. Sounds overlap, blend, and influence one another in a continuous stream known as connected speech. Add background noise, accents, and rapid delivery, and the signal reaching the ear is often incomplete or ambiguous.

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Yet we rarely notice this difficulty. We usually understand speech with remarkable speed and accuracy. This is because the brain is not waiting passively for perfect input. It actively reconstructs meaning from partial information. (Stollznow, 2026)

What Is the Ganong Effect?

One of the clearest demonstrations of this reconstructive process is the Ganong effect, first described by psychologist William Ganong. (Ganong, 1980)

In experiments, participants hear speech sounds that fall between two sounds. For example, something ambiguous between a “g” and a “k” sound. Crucially, the sound is placed in different word contexts. When the ambiguous sound precedes “-ift,” listeners tend to hear gift rather than the non-word kift. But when the same sound precedes “-iss,” they tend to hear kiss rather than giss.

In short, people are biased toward hearing real words. The brain is not just decoding sound, it’s choosing the most plausible word match.

The Ganong effect demonstrates that speech perception is not purely bottom-up (that is, data-driven). It is also top-down (i.e., our knowledge base). Bottom-up processing refers to the raw sensory input arriving from the ears. For example, hearing a word in a noisy room or a sound like a dog barking that is partially masked by other noise. Top-down processing refers to the influence of knowledge, expectations, and context. In real-world listening, these systems work together. But when speech is ambiguous, top-down knowledge often takes control, steering perception toward familiar, meaningful words.

Why the Brain “Fixes” What It Hears

This bias toward real words is not a flaw in perception. It is a feature of an efficient system. It’s also what underpins effects like the “telephone game,” where a message becomes progressively reshaped as it is passed from person to person, with each listener unconsciously imposing form, meaning, or familiar word patterns onto ambiguous input.

In everyday environments, speech is rarely pristine. The brain prioritizes meaning over acoustic precision, quickly resolving uncertainty by drawing on stored vocabulary and context. This is why we can understand a friend speaking in a noisy café or follow dialogue in a poorly recorded phone call. The brain is constantly filling in the gaps.

When the Brain Fills in the Blanks

This same mechanism also explains why we sometimes mishear speech in very specific ways. The Ganong effect is closely related to another phenomenon known as phonemic restoration. (Munechika, et al., 2026) In these cases, listeners perceive missing sounds as present when they are replaced by noise, such as a cough or static.

Even when part of a word is physically absent, the brain restores it if the context strongly supports a meaningful interpretation. In both cases, perception is shaped as much by what we expect as by what is actually there.

The Ganong effect shows that speech perception is not a passive recording of sound, but an active process of interpretation. We do not simply hear language, we negotiate it. The brain constantly balances sensory input with linguistic knowledge, resolving ambiguity in real time.

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Most of the time, this system works beautifully. Occasionally, it produces humor, like mondegreens. At other times, it reveals that perception is not objective, it is constructive.

We don’t always hear what is said. We hear what we expect to hear.

Read about this topic and more in Karen Stollznow’s new book, Beyond Words: How We Learn, Use, and Lose Language.