Our Research


“Discovery consists of seeing what everybody else has seen, hearing what everybody else has heard, and thinking what nobody else has thought” -Albert Szent-Gyorgi


Summary of research findings conducted by commercial research organisation, The Leading Edge, which conducted independent research in Australia, UK & USA in 2006 & 2007 with a combined sample size of 400 mothers & their babies:

  • 90% of all mothers reported that DBL is valuable and would recommend it to other mothers 
  • 100% of first time mothers reported it was valuable and would recommend it to other mothers
  • Significant increases in maternal self esteem and significant reductions in parental stress
  • Almost 70% of test mums reported their infant settled faster after using DBL
  • Almost 70% felt more confident as a mother and more relaxed and in control
  • Over 50% reported more unbroken sleep for themselves and their baby. 
  • 50% felt more bonded to their baby 
  • 50% believe their baby is feeding better
  • DBL not only helps mothers, but also benefited 2 out of 3 fathers, resulting in reduced levels of stress, greater paternal involvement in the baby’s care, and more positive marital relationships

Detailed background on our research to date.

It’s natural to wonder, Could this baby language be real? 

A cursory Googling with find many thousands of happy mothers blogging & reporting about their own experience. 

Amazon.com has over 100 vocal reviews alone, positive & negative. 

Academia is inclined to ignore such unscientific anecdotal evidence. After all, what would an unqualified mother possibly know? 

At the beginning.…

Priscilla made the discovery in June 1998, with the help of her family. She was not a scientist, academic or medical professional. Simply a desperate, challenged mother with a unique audio capacity to distinguish and remember sounds, in this case Pre-cry infant sounds. 

The Dunstan Classification of Infant Cries was progressively researched over the course of 8 years, at first via internal research and basic validation methods. In 2004, we enlisted the guidance of professors from Brown University in the USA who developed a research protocol for a clinical study, which was to be field tested in Australia by research collaborators at the University of Wollongong. 

In addition, we chose to work with The Leading Edge, a respected research organisation, who conducted independent studies in Australia, UK & the United States. 

The final stage by The Leading Edge & 2CV, in the USA, United Kingdom and Australia with statistically significant sample sizes, using control and trial groups and internationally recognised measures such as the Parental Stress Index & Maternal Self Esteem. 

We are happy to provide copies of the complete reports, including detailed methodologies and results to interested parties, such as any academics or researchers interested in conducting clinical studies.

In 2009, a group of nurses sent us the results of an independent research study they conducted at the Cebu Normal University College of Nursing in the Philippines. Their valuable conclusions are appended below.

There are currently no other published academic or medical papers that we are aware of that invalidates our findings anywhere in the world.

However, we are aware of a number PhD research studies that have commenced and we eagerly await their publication. 

Happily, there are a growing number of medical practitioners and nurses/midwives who have adopted the baby language into their systems. 

We believe the “real” test of DBL (Dunstan Baby Language) is the effectiveness of the system to provide “real” answers to “real” mothers. On this score, we are further supported by an estimated one million plus “real” parents who have used the system successfully, recommended it to others, written about their experiences in countless blogs and forums and reported their satisfaction levels in Amazon ratings and other consumer ratings sites. (This can be confirmed via Google.) 

The vast majority of parents report that DBL was in their own personal experience a simple, practical, effective tool – the thousands of emails and letters of thanks we have received are, of course, easy to dismiss as “anecdotal” evidence. The small minority of negative consumer experiences can be attributed to any number of factors, including the possible difficulties of post-natal depression, maternal stress & exhaustion at the time of acquiring the system, audio / hearing problems, infant conditions & illnesses. 

We welcome and would co-operate on any research academic investigators wish to conduct and would support these efforts in any way possible.

 Behavioural Impact DBL


In 2004, we enlisted the guidance of professors from Brown University in the USA who developed a research protocol for a clinical study, which was to be field tested in Australia by research collaborators at the University of Wollongong. Here is that research protocol, which contains valuable insights into the understanding of infant cries at that point in science.

The Dunstan Classification of Infant Cries.

A Research Proposal by Professor Barry Lester & Linda La Gasse

 The chief investigators are conducting the proposed research as part of an Australian trial of the Dunstan Classification of Infant Cries (DCIC) system.  The chief investigators will undertake the research as contracted research to be approved by the Innovation and Commercialization division of the University of Wollongong.  This research will be conducted on behalf of Professor Barry Lester, Professor of Psychiatry & Human Behavior and Paediatrics, Director, Infant Development, Brown Medical School and Women and Infants Hospital; and Dr Linda LaGrasse, Assistant Professor, Department of Paediatrics, Brown Medical School.  The project involves the implementation of an existing research protocol.  The protocol by Lester and LaGrasse is presented below.  It has been modified in sections to suit local conditions.

Research on infant cry has demonstrated associations between cry characteristics and medical/neurological compromise in infancy.  Specifically, studies have shown associations between cry characteristics such as latency, duration, variability in fundamental frequency, amplitude and neurobiological risk indices (Blinick, Travolga, Antopoc, 1971; Corwin, Golub, & Potter, 1987; Corwin, Lester, & Golub, 1996; Corwin, Lester, Sepkoski, et al., 1992; Huntington, Hans, & Zeskind, 1990; Lester, Corwin, Sepkoski, et al., 1991; Lester & Dreher, 1989; Nugent, Lester, Greene, et al., 1996; Zeskind & Lester, 1981).  Furthermore, previous research has demonstrated relations between infant cry characteristics and child outcome (i.e., neurological impairment and death) in infants affected by risk factors such as asphyxia, brain damage, Down syndrome, and other genetic anomalies (Fisichelli, Coxe, & Rosenfeld, 1966; Fisichelli & Karellitz, 1980; Golub & Corwin, 1982; Karellitz & Fisichelli, 1962; Lind, Vuorenski, Rosberg, et al., 1970; Michelsson, 1971; Michelsson, Sirviö, & Wasz-Höckert, 1977a,b; Ostwald, Peltzman, Greenberg, et al., 1970).  The data suggest that infant cry is an indicator of biological and neurological risk.

There are two key aspects of cry: (1) the cry itself, which is innervated by the cranial nerves modulating the autonomic nervous system and signals emergency status;  (2) the salience of the cry to any potential caretakers in the environment, producing a visceral reaction that compels action (LaGasse, 2005).  The Biosocial Model of Infant Cry (BMIC) suggests that infant cry may also be used as an indicator of specific developmental processes (Lester, 1984a).  Specifically, the BMIC identifies two distinct pathways from infant cry to outcome: (1) a Direct Pathway and (2) an Indirect Pathway (Lester, 1984a; Lester & Boukydis, 1992).  The Direct Pathway suggests that infant cry reflects neurobiological status, which contributes directly to child outcome.  The Indirect Pathway suggests that infant cry acts as a social signal that affects the caregiver; the caregiver, in turn, influences the child’s outcome.  In other words, infant cry also contributes to child outcome by modifying caregiving responses to the infant. Research in the area of cry perception suggests that such a pathway exists.  Specifically, previous research has shown that cry acoustics influence listeners’ perception of cry as aversive, sick, urgent, distressing or arousing (Adachi, Murai, Okada, Nihei, 1985; Gustafson & Green, 1989; Okada, Murai, & Adachi, 1987; Protopapas & Eimas, 1997; Schuetze, Zeskind, & Eiden, 2003; Schuetze & Zeskind, 2001; Zeskind & Lester 1978; Zeskind & Marshall 1988).  Furthermore, listeners’ ratings of cry samples along these dimensions are associated with their own reports of likelihood to provide and type of caregiving (Leger, Merrit, Thompson, et al., 1996; Gustafson & Green, 1989; Wood & Gustafson, 2001; Zeskind, Klein, & Marshall, 1992).  However, there are no studies that have related cry acoustics to observed caregiver behaviour or the caregiving environment.  The closest study to examine this was conducted by Lester and colleagues (Lester, Boukydis and García-Coll, 1995).  They found that infants of mothers who more accurately identified their infant’s cry as aversive or as not aversive (based on the fundamental frequency of cry) had higher cognitive and language scores at 18 months than infants whose mothers misperceived their infant’s cry signal.  The authors hypothesized that caregiving behaviour moderated the association between the “Goodness of Fit” of infant cry and maternal perception with outcome. 

The present study represents an important departure from this previous work. As with previous work, it is based on the idea that there are messages encoded in the infant’s cry. However, instead of trying to identify these meanings from their acoustical characteristics, we propose to study the effectiveness of a system (Belo) that catalogues the language of infant cry.

Until recently, communication was thought of as consisting mostly of language, and since infants do not talk, they were considered incapable of communication (Lester 1984). However, infant crying contains linguistically salient aspects of human speech that are physiologically based and adapted for communication. Human speech is divided into linguistic and paralinguistic or suprasegmental aspects. The linguistic or lexical components refer to the elements, which develop meaning, as phonemes become syllables and words to be organized into phrases and sentences by rules of syntax. Qualitative aspects of speech, the intonation patterns, inflection, stress, intensity, and general melody form constitute the paralinguistic component. These so called “prosodic” features of speech have their acoustical correlates in the timing (duration) amplitude (intensity) and fundamental frequency (dominant pitch) of phonation. It is these features that convey attitudes and emotional states.  Communication relies heavily on these prosodic features of speech. They are the first aspects of language to appear in the vocal behaviour of the human infant, the cry. Thus, infant crying is part of the matrix for later language development (Lester, 1984).

The purpose of this study is to evaluate the validity and effectiveness of the DCIC that links unique infant sounds to specific needs.  The DCIC aims to teach mothers how to detect certain sounds of their baby and the meaning of these sounds. Previous pilot work has shown the DCIC approach to be easily understood and applied by mothers who report many benefits including their own satisfaction with parenting and improved sleep and feeding in the infants.  This study is a randomized clinical trial (RCT) with 50 mother/infant pairs in the intervention arm, 50 in one control group and 25 in a third control group. Subjects are recruited when the babies are 3 weeks of age. Infants will be full term, normal, healthy. Mothers will be middle class with no psychiatric problems, half primiparous, half multiparous. The intervention arm involves teaching the DCIC to the mothers and the control arm involves teaching mothers about infants’ needs and settling techniques. The third control group will receive no intervention.

Baseline crying (who and how eg. diary to record crying) and other background maternal and demographic variables will be recorded at home. Mothers will then be trained in the intervention or control arm using videotape and written materials. Then there will be a follow-up one month after the intervention to determine intervention effects. These effects will be measured as changes in infant crying and sleep and maternal measures. Infant crying, sleep feeding and awake time will be measured by having the mothers keep 3 day daily diaries during pre- and post-test.  During these periods, infant sounds and crying are recorded. Other pre- and post-test measures include the Hamilton Depression Rating Scale, Speilberger State-Trait Anxiety Scale, Parenting Stress Index, Family Assessment Device, Maternal Self Esteem, Maternal Attachment Scale, and the Perceived Stress Questionnaire.  The Infant Behavior Questionnaire (infant temperament) and the Satisfaction Survey are administered post-test only.  Research assistants and raters of infants’ sounds are blind to group status. Only the project coordinator has access to group assignment.


 This study is a randomized clinical trial of 125 mother/infant pairs.  Mothers (half primiparous, half multiparous) will be randomly assigned to one of three arms – treatment or one of two control groups.  Mothers in the intervention group will be taught the DCIC system and also settling techniques that they can use with their baby.  Mothers in one of the control groups will be taught settling techniques only.  Mothers in the third group will receive just the diaries and recorders.  Mothers will be blinded to the group they have been assigned to.  The researchers will be responsible for random allocation

The study protocol is outlined in Table 1.  Baseline crying and other background maternal and demographic variables will be recorded at home.  Mothers will then be trained in the intervention or control arms using a videotape.  To determine intervention effects, changes from baseline to post-test in infant crying and maternal measures will be examined.  Infant crying, sleep feeding and awake time will be measured by having mothers keep 2 day daily diaries during pre and post test.  During these periods, infant sounds and crying are recorded. Videotaping of crying bouts is optional (Table 1).  If mothers do not consent the Research Assistant (RA) can complete the diary when the child cries, simultaneously but independently of mother.  The cry would be recorded on audiotape and the cry and diary are time synchronized.  The RA and rater of infants’ sounds are blinded to group status. 

Table 1

Study Protocol 


Age of infant




< 3 wks


Contact; Determine eligibility; Explain the study; Schedule first visit


^1st Home visit



3 wk ± 1 wk

2 days

Study explained and mother gives written consent; all mothers complete the questionnaires and are trained on maintaining the written diary. 

For 2 days –diary and audiotape of babies crying is taken (date time annotated in 15 min intervals on a clip board with lighted clock) and placement of recorder (voice activated with time, date stamp).

Training 1: DCIC system (Rx grp)  2nd home visit

3 wk 3 days ± 1 wk

1 day

Diary and audiotape are collected. All mothers and infants are videotaped during 1 cry bout until ended; RA and mother independently complete the diary for that episode.Pre – test: All mothers watch a test video of babies making the 5 sounds. Mothers are asked to identify the meaning of the baby’s sound on a questionnaire and how confident they were about their decision.Training 1:  Rx group – receive training video of DCIC system for 3 sounds (most commonly used) and a chart with the 3 sounds and their meaning.Controls – nil.

Training 2:  DCIC system (Rx grp) 3rd home visit

4 wk 3 days ± 1 wk

7 days

One week later, all mothers are post-tested (time 1) using the test video to assess whether mothers in the Rx group are able to identify the 3 sounds and determine any changes over time.Training 2: After post-testing, mothers in the Rx grp will receive another video for training on remaining 2 sounds and settling techniques. Control grp – receive training video of same settling techniques given to Rx grp. 

Using system

4 wk 3 days ± 1 wk

14 days

Mothers in the Rx group will use the DCIC system (all 5 sounds) and settling techniques for 14 days.      Control grp – use settling techniques for 14 days.     


6 wk 3 days ± 1 wk

14 days

All mothers – for 2 days – written diary and audiotape of babies crying is taken (date time annotated in 15 min intervals on a clip board with lighted clock) and placement of recorder (voice activated with time, date stamp). 

Post-test   4th home visit

6 wk 5 days ± 1 wk

2 day

All mothers complete baseline questionnaires again and are asked to identify the meaning of the baby’s sound in the video. All mothers are post-tested (time 2) with the test video. Mother and infant are videotaped during 1 cry bout until ended; RA and mother independently complete the diary for that episode. 



 Mothers in this study will be middle class with no psychiatric problems; are breastfeeding their infant.  Mothers will be excluded from the study if they are less than 19 years of age; have a history of institutionalization fro psychiatric reasons; didn’t complete secondary level schooling; has a current psychiatric diagnosis, and/or is on psychotropic medication; has no partner (married or de facto) and have significant hearing and or visual problems and or are not fluent in English.  Infants will be excluded if they are preterm, low birth weight, and/or any time in NICU; have congenital malformations, genetic condition and or medical problems, and are colic and/or milk allergic.

The same inclusion and exclusion criteria apply to the participants in the control groups.


Mothers complete the following questionnaires at the beginning and at the end of the study. Changes in these questionnaire scores will be used as additional measurement of the effectiveness of the intervention. The questionnaires include:

  • Demographics Questionnaire
  • Hamilton Depression Inventory [measures maternal depression]
  • Speilberger State-Trait Anxiety Scale [measures maternal anxiety]
  • Parenting Stress Index [measures perceived stress related to parenting]
  • Family Assessment Device [measures family process, e.g., cohesion / conflict resolution]
  • Maternal Self Esteem (measure self esteem related to parenting]
  • Maternal Attachment Questionnaire   [measures maternal feelings of attachment to baby]
  • Perceived Stress Questionnaire [measures perceived stress]
  • Infant Behavior Questionnaire [measures infant temperament. e.g., distress, orienting, soothability]

Mothers will be recruited from the antenatal sections of hospitals in the South Eastern Sydney and Illawarra that agree to participate in this study. An information session information relevant staff at participants will also be held.   Mothers will also be approached from surrounding local community centres.  Information Sheets will be placed at these venues.