Critical Learning Period

By Chelsea Biondolillo

Featured Art: Designs for Wallpaper and Textiles: Birds


Songbirds, or Oscine Passeriformes, with fixed song repertoires learn to sing in four steps. The steps are studied, in part, because many linguists believe that these same four steps describe human language acquisition.

The first step in song acquisition is called the critical learning period. This is when chicks begin to recognize their parents’ voices along with neighbors of the same species, and they differentiate between those voices and other sounds.

My parents were married for three years before I was born, and they lived together for almost three years after. The shape and sound of their love is un- known to me. I have no idea how he courted her or when the courting became something else. I do not remember the words they spoke to each other in the days and months while I lay in my crib, listening.

I know what my mother said to me and what I said back. These are stories I’ve heard often. Before I could talk, I had night terrors, she tells me. I would scream inconsolably in my sleep. The pediatrician said this was normal for some babies. She tells me about the day I choked on bottle milk while lying in my crib, and how the sound of it sent her running to me; how afterwards, I would choke and gag whenever I wanted her to pick me up. It was a sound she could never ignore, she says, eyes squinted theatrically at the memory of my manipulation.

I would stand in my crib and yell (so early! so advanced!) MOM. MOM. MOM. MOM. And then one day, after a moment, DARLENE. I wonder, now, if I sounded like my father when I said it.


A chick in the silent stage of development might make alarm sounds or cry for food, but it does not sing. This period can last up to eight months. A number of ornithological research studies document that a range of memorization and comprehension activities are occurring during this stage.


I would’ve been memorizing and comprehending while my parents’ relation- ship collapsed. I have only two vivid memories from that time, and both are soundless. One is of watching Sesame Street while my mother did seventies-style calisthenics in front of the couch, next to me. The other is of my father throwing clothes out of a dresser drawer. For years, this memory seemed to be of a comic gesture, something he might have done to make me laugh. My point of view was low-angled, as though I were standing in the doorway to their room, which is long in my mind’s eye with dreamlike perspective, like a hallway, at the far end of which was their bed. The memory itself is just a flash, no more than a six-second clip of motion: arms, clothes arcing up and over. Years later, after my mother told me about the night we left, the nights leading up to our leaving, I realized that he was not performing for me. He was tearing their shared bedroom apart looking for evidence, for proof.


Studies on white-crowned sparrow song learning pre-date the studies of Stephen Krashen, a linguistics and education scholar, whose input hypothesis describes how secondary languages are acquired in human speakers. Krashen never mentioned birds, but his own work underscores the importance of the silent period. He believed that comprehension naturally led to communication. Though some of Krashen’s arguments are thoughtfully criticized now, they influenced language learning programs for decades, and continue to do so.


Over good wine and a perfectly grilled steak, my latest lover tells me all of the things his ex-girlfriend didn’t like, wouldn’t do, failed to appreciate. Each exasperation has a moral; it’s a little lesson I’m to learn. He calls this sharing himself, and I hear myself repeat back to him, Yes. Please. Thank you.


Before I was born, my mother sold light bulbs door-to-door while my father was at work. This made it difficult for him to monitor her, so he pressured her to go back to restaurant work.

At the restaurant, he could drop in from time to time. He could check to make sure she wasn’t flirting any more than was necessary to get her tips. When she told me about the light bulb job, I was in grade school and using her old sample case to cart around my art supplies. It had a socket housing at one end. She must have been able to screw a bulb into it for demonstration purposes. When she told me about having to go back to the restaurant, I was an adult. By then, I was familiar with what it felt like to be monitored by my lover.


“Both humans and songbirds learn their complex vocalizations early in life, exhibiting a strong dependence on hearing the adults they will imitate, as well as themselves as they practice, and a waning of this dependence as they mature.”

—“Birdsong and Human Speech,” Doupe and Kuhl, Annual Review
of Neuroscience,


Recent work with zebra finches shows that certain neural gates open or close when young birds are learning songs from their male tutors. As fathers sing new pieces of song, “learning” neurons fire, but pieces of song that the chicks have already learned do not have the same effect. In fact, when they hear a song repeated, an inhibitory response is triggered in their brains. The researchers track these responses using implanted electrodes, weighing less than a penny, on “freely flying” finches.

One of the researchers says of their findings, “We see that the brain changes how it listens to the father once it’s learned part of that song.” She finds that sweet.


I don’t remember my first breakdown, because I have cried a lot for as long as I can remember. I cry when I’m tired, when I’m frustrated, hurt, sad, scared, whenever I am overwhelmed. But at some point, during my last year living at home, and my third year in college, I tried to talk to my mother about it.

I had been afraid to tell my mother that the crying worried me, that it sometimes seemed a thing out of my control, like a car still rolling forward though my foot was mashed into the brakes. My skin felt hot and my stomach churned when I imagined the words I would have to say. Words like hysterical, and maybe even crazy. I have been afraid of other conversations in my life; it always feels like this. This time, I was most afraid that she would just say to try harder and I couldn’t imagine how to do that.

Instead, she said, “Maybe you were awake the night we left. I thought you were asleep, but maybe you were awake.”


When I’m alone in the house, and my lover is far away on one of his frequent business trips, I sit down on the area rug I bought—to protect his Peruvian mahogany floors from the sharp edges of my secondhand coffee table—and attempt to call up the loudest sobs I can. No one can hear you, I tell myself. Now is the time to get it all out. I think about his small cruelties, his reminders, admonishments, the long months of summer stretching before me. But I almost never make a sound.


During the next phase of their learning, baby birds practice the sounds of their song without actually communicating information. The subsong has been likened to “babbling” and has also been called a period of “vocal play.” I learn in an ornithology textbook that individuality is important to birds, too. They transform and improvise from the collection of themes and syllables that were memorized in stage one.

During a lecture on birdsong acquisition, a professor of mine mentioned that birds deafened prior to or during the subsong period would never be able to effectively reproduce a song recognizable to other birds.

I’d been interested in birdsong for years before this class. I could distinguish the raspy song of red-winged blackbirds from the other feeder visitors at a very early age. I was able to mimic towhees, jays, robins, and finches by grade school. But this idea of birds being “deafened” was new. It was a word that required investigation. A glance at the methodology sections of several papers found mention of lesions, implants, and pharmacological interventions. During studies like these, birds are induced to sing in a variety of ways: the removal of their mate or parent, recordings of known or unknown individual birds playing nearby, and by electric stimulation (via implanted surgical steel electrodes). Researchers who use these methods are supposed to follow humane procedures so as to minimize animal pain, suffering, and distress.


He was drunk at the time, she said, and in the throes of one of his paranoid fantasies about infidelity. He raged. He had a gun, and later, a knife. He was threatening to hurt her, and himself. When he finally passed out, she bundled me up. We left. I don’t remember any of this, and can’t imagine it, because I can’t picture my father doing any of these things. He has never had a drink of any alcohol in my presence. She said so little against him when I was young and she never denied his rare weekend visitation requests. Though I can’t imagine it, I know it’s true. Something in my quickening pulse must remember it, even if I can’t call the memory up.

In high school, snooping around an old file cabinet of my mother’s, I found a poem written in his handwriting. It was melancholy and dramatic and not very good. The only words I remember are “tears” and “gray.” I don’t know if he wrote it to her or for her or if he just wrote it and it was stuck in between other papers that she needed to keep. I stuffed it back where I found it and mentioned nothing for over twenty years.

As soon as I told her that I’d once found such a poem, she said she probably still had it somewhere. “You know how I keep things,” she added.


My mother tells me my father had no patience for fussing. If we were at some- one’s house and I began crying or whining, “like a baby,” she explains, like I was supposed to, she means, we’d have to leave.

I tell her, perplexed, but not with any disbelief, that I have seen very little of this side of his anger.

“I guess I inspired it in him,” she says, in my voice.

Yes. Please. Thank you.

I assure her that I’ve heard similar sentiments from his ex-wives and their children. “If you did, it wasn’t personal,” I say.


“But most of the finer detail of the song is learnt by the young bird when, in its first breeding season, it first comes to sing in competition with neighbouring territory holders. There is little doubt that this is the way in which local song- dialects are built up and perpetuated. Full [songbird] song is thus an integration of inborn and learned song patterns, the former constituting the basis for the latter.”

—“The Learning Of Song Patterns By Birds . . . ,” W. H. Thorpe,
Ibis, 1958


My mother would sew my dolls dresses from fabric scraps and once, she converted a particle board bookcase into a four-story Barbie Dreamhouse with some leftover carpet corners and contact paper. Many of my own first art sup- plies came from her stash.

She also taught me to succeed. I stayed up all night to finish projects on time. I worked two jobs to save enough money for my first year of college. After my own marriage ended, I took every promotion I could get until I had a down payment for a house. If you do what needs to be done, things will always work out: this is my mother’s song.

But in looking up the gruesome details of songbird experiments, I find this: songs are learned from conversations just as much as from tutors. I know so little about the conversations that I heard first. I worry often about the things I learned to say in my father’s voice. About my own predilections toward any voice that sounds like his.

But too, about the sound my voice still makes crying out in defiance of his demands, even though I have disavowed his demands for decades.


The final step is to turn the babbled song into an adult song. It can happen within weeks of the young bird’s first attempts, or it can take months, depending on the species. The bird picks a few sounds from his practice and then organizes them into phrases and perfects their timing, such that he can communicate with others of the same species.


When I try to ask my mother about our time in my father’s house, she chooses words carefully. “It is extremely difficult to live under the scrutiny of a jealous person.”

I explain the critical learning period, about wanting to know more about the first words I heard. I do not say that I am waiting for someone to come home, that when he does, I will talk to him in a voice I don’t recognize. I’m afraid that she might tell me to stop trying, to get as far away as I can. I will, and soon, but today I can’t yet imagine how to do that.

“You would’ve heard some very ugly things. Some very . . . ugly things.” I can hear her mind stumbling and skipping, with regret perhaps, or possibly, sudden insight. My skin gets warm and I don’t want to hang up the phone with this widening space between us.

Sometimes knowledge is a burden you can carry for someone else. I want to take this knowing from her and pack it back up.

I tell her that even scientific analogies have their limits. I tell her starlings and mockingbirds continue to learn songs throughout adulthood. I tell her about the zebra finches, how they learn to ignore the sound of their fathers’ voices.

“That’s reassuring,” she says.

I pace in front of the large picture windows with a dust mop in my hands and the phone in the crook of my shoulder. The windows let in so much sunlight. I imagined it would be good light to work by—the way it glows like certain magazine spreads on his fine wood floors. But it only does that when the wood is spotless, I’ve learned. And keeping it spotless takes a lot of work. Outside, a juniper titmouse, then a junco, then a rock dove, stop by the porch in search of food. One by one, they find none.

“Plus, we aren’t birds,” I say. “That’s true. We aren’t.”

I shake the dust mop out over the trash and move to the broom. We start talking about birthdays. Mine is coming up and there are so many after that, in August. Among them, my father’s, which neither of us mentions; among them, my lover’s. I’ve been knitting him a pair of socks. He’ll only put them on once, when I ask to see if they fit. I’ll take them with me when I leave.

Chelsea Biondolillo is the author of The Skinned Bird: Essays, and two prose chapbooks, Ologies and #Lovesong. Her work has been collected in Best American Science and Nature Essays 2016, How We Speak to One Another: An Essay Daily Reader, Waveform: Twenty-first Century Essays by Women, and others. She has an MFA in nonfiction and environmental studies from the University of Wyoming and lives outside Portland, Oregon.

Originally published in Issue 19.

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