Freud instructed his patients to say what was on their minds – to “free associate”. As he moved on from the practice of hypnosis and published the first results of the talking cure in 1895, he was asking his patients to replace a doctor’s words and instructions with words of their own. Unlike other medical practitioners of the time, he would not tell. He would first listen and then listen some more.

With this instruction he disrupted the conventional doctor-patient relationship as well as the back and forth of polite conversation. Patients were to lie on the couch out of his sightline and they were to say whatever came into their minds.

By allowing for space around the utterances of his patients, he hoped to free them from traumas that were buried, unconscious or expressed through hysterical symptoms. At that time, the occurrence of non-biologically based physical symptoms, such as a paralysed arm or leg, was widespread. Each age throws up its own complaints. Think of the pervasiveness of bulimia, anorexia and eating troubles today, while the 19th century was replete with hysterias. Freud’s aim was to enable the individual to encounter the conflicts these hysterias held, and experience, rather than repress, the knowledge of them. He believed that through talking freely, the difficult conflict could be borne and the symptom would dissolve. His liberatory aim created a revolutionary practice: the idea that patients could, through their own speech, discover what so troubled them and in turn, heal themselves.

Freud had followed the associations of his own night-time dreams wherever they led his mind. The jumble of seemingly incongruous images and words were analysed to reveal the desires repressed in daily life. He found the workings of his own psyche fascinating and illuminating and, as he deployed the method with his patients, he began to build the theories that became the cornerstone of psychoanalytic practice: listening, observing, feeling, reflecting. The interpretations he was to offer have now, alas, become so culturally cliched that they can hide the revolutionary nature of the talking cure, a practice which has endured and developed over the past century.

Words are the most exquisite example of the unity of mind and body. Speech is a physical and mental production and the tone, rhythms and forms in which words are spoken in the analytic session are of great interest. Do the words come tumbling out and then stop abruptly? Are they slow to come? Are they staccato or interrogative in the stereotypical manner of the “valley girls”, whose every utterance ends in a high? Are they halting or sparse? Like music’s tempo, melody, chords and notes, words in an analytic session – how they are used and the way they are said as well as the spaces between – form a structure.

In the early stages of therapy, as the words are spoken, the therapist may wonder to whom they are addressed. In tonal terms they perhaps express grievances that can’t be articulated to the mother, the teacher, the father, the grandparent or the sibling. The therapist has become a proxy for someone else and may hear judgments projected on to her or him that only make sense if the therapist is understood as a stand-in, an “as if” relationship.

As accusation gives way to feelings and new understanding, words take on a different weight. They are pruned and examined until they are just right: spare and evocative like words put together for a poem.

The therapist listens to the words, to what they aim to convey, to the vocabulary and to the rhythm. She also listens to constraints in the vocabulary and the repetitive manner in which the stories or incidents are told. She asks herself: why this refrain? Why this slip of the tongue here? Why this chain of associations?

For the therapist, the refrains of repeated stories are both clue and trope. They can conceal and reveal the individual, or analysand, at the same time. An oft-repeated story by a younger sister overshadowed by her older sister, which remains unrelieved in the telling or in the sharing of the feelings, cues the therapist into the words and feelings that are unexplored.

The telling has become a cover story. It’s not that the older sister’s behaviour didn’t cause hurt, but it is a story that is insufficient. It is decontextualised; severed from the larger familial and cultural set-up in which that hurt was able to prosper.

Each person’s clues are idiosyncratic and entirely personal. Defence structures – those aspects of the self which aim to protect the psyche from what has been unmanageable – have recognisable forms, but the ways in which they develop are distinctive and individual. Finding the right words to interrupt these patterns requires close listening. The therapist needs to feel the words as though they were his or her own in order to find a response that respects their rhythm, yet is able to offer something sufficiently novel to break the psychic log jam.

Like works of literature which introduce us to characters with increasing complexity and depth, the psychoanalytic endeavour involves the analyst and analysand in a quest to understand a multi-layered inner world. The analysand is consciously in search of change, even as she or he may resist it. The tension between the discomfort of the known and the fear of the as‑yet‑not-experienced is part of therapy’s dialectic.

As the deconstruction of known senses of self occurs, the words, timbre and tone may change. The therapist becomes alert to movement in language, to the disruption in the speech pattern, to the elements of surprise or reflection that halt a well-honed tale in its tracks, so that story or incident can be thought and felt about anew. The therapist’s language is particular to encounters with that individual. It is not therapy speak or psycho-babble. It is a bespoke relationship with a bespoke language.

And within that bespoke relationship, as words are discarded and new words found, the therapeutic couple create an aesthetic with its own unique colour, temperature and shape. The stormy moments give way to an adagio, not just one but several, which build and then turn back to re-examine understanding and mood. There are resting points and times of quiet which hold the therapeutic couple in their work together.

Together, these undergird the challenges and struggles that psychological change demands. The aesthetic emerges out of the in vivo study of mind and emotion and creates its own satisfying forms. Amid the pain, sweat, struggle, times of confusion and misunderstanding, small pleasing connections and new understandings occur which have their own beauty – not dissimilar to the elegance physicists and mathematicians talk of when they find pleasing explanations.

Curiously, the technical language of psychoanalysis is quite ugly and crude, but the words and ideas that emerge in sessions sing. Therapists discover that their own vocabularies are enriched by stretching to understand the subtlety of their analysands’ feelings and ways of being. The therapist may utter words they never knew they knew or had spoken before. The concepts that were suddenly urgent to explain, or the feeling that required meeting, produce new language and words in an order outside of ordinary conversation. That too has its beauty and its satisfactions.

In everyday chatter we can on occasion be surprised by what we say, but the structure and purposeful endeavour of the analytic hour creates a space in which surprise can occur frequently. One notices what one says and what one cannot say. The therapist, too, notices not just what the analysand says or doesn’t say but what she or he can and cannot say.

The injunction to speak freely does not mean that words necessarily flow for either party. It means that out of the jumble or the silence, words will in time be found, feelings will be recognised. Interestingly, the therapist’s interrogation of his or her responses is part of deepening the understanding of the analysand’s story; how is it, the therapist asks herself, that I feel silenced, inarticulate or perhaps garrulous? What does it say about me, but more importantly what does it say about the kind of relationship the analysand has experienced and is now creating with me in the therapy?

What is made of it at the level of the analysis contributes to the talking cure and is an essential aspect of clinical theory-making.

As one who both writes and listens, I am often struck by how the talking/listening cure is not dissimilar to what happens with words when one is writing. Writing takes us to places we had not anticipated and shocks us with its new, unthought knowledge. This is why many of us write. We want to find out what we didn’t know we were thinking and feeling. We want to give shape to inchoate thoughts that need gathering and sorting.

The exhilaration of a new idea or wisdom, or a different emphasis, is what can relieve the often hard work of putting words on the page. It is the nuance, the refashioning, that catches our breath, while it subtly resituates us inside ourselves.

But as in any attempt to articulate what feels right, words in therapy aren’t all cosy or satisfying. Thoughts and feelings can be saturated with malice and sometimes this is directed at the therapist. The therapist can’t escape this if she is to do her job. She needs to find the resilience to experience the blow, and then think about what it expresses. Ugly, harsh, malevolent, envious, cruel words can tell us about difficulties often too painful to bear. Instead they are projected out (and on to the therapist) with fury, because difficult feelings –perhaps of need or dependency or helplessness – have been internally rejected.

This is the work of therapy: to find the words which can enable the individual to encounter the complexity of feelings that they find fearful and to then risk experiencing them. This can be initially for no more than a moment, but gradually for longer, until such feelings can live inside them without being a source of terror. Or, as Freud would have said, they can turn from hysteria into ordinary human unhappiness.

• Susie Orbach’s In Therapy is published by Profile books and Wellcome Collection. The second series of In Therapy begins on BBC Radio 4 on 7 November at 12.04pm.