Vocal Characteristics Research Articles

Subtitling for people with hearing impairments in the Arab world context: The case of <i>the Blue Elephant 2</i> movie

Although technology advancements have increased the availability of screens everywhere, making it possible to watch AV products anytime, the deaf-and-hard-of-hearing (DHH) accessibility to these materials in the Arab world is still poor. Only a few Arabic movies with this feature are available via Netflix. In this study, the subtitles for the deaf and hard of hearing (SDH) in <i>The Blue Elephant 2</i> movie are analyzed. This study qualitatively examines the type of information covered in the subtitles of the investigated Arabic movie for Arab viewers with hearing impairment. It also quantitatively investigates the reactions of people with hearing impairment to the technical aspects of the subtitles using a structured questionnaire, which consisted of five open-ended questions. The qualitative analysis revealed two main types of information, namely, para-linguistic/extra-linguistic and linguistic. The para-linguistic/extra-linguistic aspect includes information about music, speakers, vocal non-linguistic features, and non-verbal signs. The linguistic aspect is related to the code-switching between languages where the speaker may use some languages other than Arabic. The quantitative analysis showed that the participants reacted positively to the technical aspects of the subtitles, including the length and synchrony. They stated that they had enough time to read and process the information included in the subtitles. The paralinguistic information was reflected in the subtitles and helped them better understand the movie. The sample attitude towards SDH was good and positive, and they like to watch more Arabic movies with this feature in the future. This study concludes that more attention to DHH people in terms of accessibility to audiovisual content should be paid. This will likely improve their linguistic and cultural skills and help them integrate more with the surrounding community. The study’s findings have substantial implications for enhancing DHH individuals’ access to audiovisual content in Jordan and the wider Arab region. The study emphasizes the need to deliver high-quality SDH that incorporates both linguistic and paralinguistic information to DHH viewers in order to improve their viewing experience.

Spectrographic Vocal Characteristics in Female Teachers: Finger Kazoo Intensive Short-term Vocal Therapy

Verify the results from intensive short-term vocal therapy using the Finger Kazoo technique about the spectrographic vocal measurements of teachers. Controlled and randomized trial. Spectrographic vocal assessment was performed by judges before and after intensive short-term vocal therapy with Finger Kazoo. Sample was composed of 41 female teachers. There were two study groups (with vocal nodules and without structural affection of the vocal folds) and the respective control groups. For the statistical analysis of the data, nonparametric tests were used (Mann-Whitney test and Wilcoxon test). After intensive short-term vocal therapy with Finger Kazoo, improvement in voice spectral parameters, such as improvement in tracing (color intensity and regularity), greater definition of formants and harmonics, increased replacement of harmonics by noise, and a greater number of harmonics, mainly in the group without structural affection of the vocal folds. There was an improvement in the spectrographic vocal parameters, showing greater stability, quality, and projection of the emission, especially in female teachers without structural affection of the vocal folds.

Optical Flow Analysis of Paralaryngeal Muscle Movement.

The paralaryngeal muscles are thought to be hyperfunctional with phonation in patients with primary muscle tension dysphonia (pMTD). However, objective, quantitative tools to assess paralaryngeal movement patterns lack. The objectives of this study were to (1) validate the use of optical flow to characterize paralaryngeal movement patterns with phonation, (2) characterize phonatory optical flow velocities and variability of the paralaryngeal muscles before and after a vocal load challenge, and (3) compare phonatory optical flow measures to standard laryngoscopic, acoustic, and self-perceptual assessments. Phonatory movement velocities and variability of the paralaryngeal muscles at vocal onsets and offsets were quantified from ultrasound videos and optical flow methods across 42 subjects with and without a diagnosis of pMTD, before and after a vocal load challenge. Severity of laryngoscopic mediolateral supraglottic compression, acoustic perturbation, and ratings of vocal effort and discomfort were also obtained at both time points. There were no significant differences in optical flow measures of the paralaryngeal muscles with phonation between patients with pMTD and controls. Patients with pMTD had significantly more supraglottic compression, higher acoustic perturbations, and higher vocal effort and vocal tract discomfort ratings. Vocal load had a significant effect on vocal effort and discomfort but not on supraglottic compression, acoustics, or optical flow measures of the paralaryngeal muscles. Optical flow methods can be used to study paralaryngeal muscle movement velocity and variability patterns during vocal productions, although the role of the paralaryngeal in pMTD diagnostics (e.g., vocal hyperfunction) remains suspect. 2 Laryngoscope, 134:1792-1801, 2024.

Extracting vocal characteristics and calculating vocal synchrony using Praat and R: A tutorial

In clinical research, the dependence of the results on the methods used is frequently discussed. In research on nonverbal synchrony, human ratings or automated methods do not lead to congruent results. Even when automated methods are used, the choice of the method and parameter settings are important to obtain congruent results. However, these are often insufficiently reported and do not meet the standard of transparency and reproducibility. This tutorial is aimed at researchers who are not familiar with the software Praat and R and shows in detail how to extract acoustic features like fundamental frequency or speech rate from video or audio files in conversations. Furthermore, it is presented how vocal synchrony indices can be calculated from these characteristics to represent how well two interaction partners vocally adapt to each other. All used scripts as well as a minimal example, can be found on the Open Science Framework and Github.

Pronunciation of English velar nasal (angma) by undergraduate students in Pakistani universities

Pakistani English (PakE) is an emerging variety of English that is in the process of developing its own norms and standards. Besides, distinguishing lexical and syntactic structures, it also has unique phonological features (Baumgardner, 1993; Hassan, 2004; Rahman 1991). Many Pakistani linguists have discussed unique consonantal and vocalic features of Pakistani English (PakE). However, there has not been any significant research conducted on the pronunciation of English velar nasal or angma /ŋ/ by Pakistani English speakers. This study analyses the pronunciation of English velar nasal by Pakistani English speakers. The sample was selected from 20 undergraduate students of the Department of English studying in the first semester of a large-scale public sector university located in Lahore, Punjab, Pakistan. A number of 20 English lexical items were selected and were divided into three categories according to the distribution of angma in the English language. The items were presented to the participants in diagnostic sentences. PRAAT, the speech and phonetics analysis software, was used to analyse the data. The findings revealed that Pakistani English speakers pronounce angma inaccurately in the medial position and insert velar plosive /ɡ/ in the poly-morphemic words. However, in the final position, angma is pronounced correctly by most Pakistani English speakers. The findings highlight that Pakistani English speakers are not concerned about the morpheme boundary and pronounce angma without /ŋɡ/ coalescence. Thus, it is found that Pakistani English speakers have distinguished pronunciation. The study recommends more research on Pakistani English pronunciation as well.

Platelet-rich plasma in treatment of scar, atrophy, and sulcus: Short- and long-term results.

Platelet-rich plasma (PRP) is rich in growth factors and is easily obtained from blood samples. Long-term data after PRP injection into the larynx should be improved. This study reports the short-term (3 months) and long-term (12 months) voice results after PRP injection. Sixty-three patients with scars (n = 34), sulcus vocalis (n = 17), recalcitrant nodules (n = 5), atrophy (n = 4), or a combination of these (n = 3) were included (158 injections; median follow-up = 12.3 months). Stroboscopy, voice handicap index (VHI-10), and cepstral spectral index of dysphonia (CSID) before and after treatment (3 months) and at 12 months were tabulated. VHI-10 changed from 19.5 to 14 at 3 months and 21 to 15 in the long term. The CSID scores improved from 31 to 21 in the short term and 31 to 26 in the long term (p < 0.001, paired t-test). Patients reported improved vocal effort and stamina with slight VHI or CSID score changes. Stroboscopy revealed improved closure and mucosal waves. Patients with severe dysphonia were less likely to improve compared to those with mild to moderate dysphonia. Some patients showed short-term improvements and then deteriorated back to baseline CSID over time (p < .05, paired t-test). Both short- and long-term improvements in voice following PRP injection have been reported. Patients with mild-to-moderate dysphonia had better outcomes. PRP injection is an alternative treatment for patients with mild-to-moderate dysphonia due to vocal fold scarring, sulcus, and atrophy. II Prospective case series treatment.

The Influence of Multisensory Input On Voice Perception and Production Using Immersive Virtual Reality

The purpose was to examine the influence of auditory vs visual vs combined audiovisual input on perception and production of one's own voice, using immersive virtual reality technology. Thirty-one vocally healthy men and women were investigated under 18 sensory input conditions, using immersive virtual reality technology. Conditions included two auditory rooms with varying reverberation times, two visual rooms with varying volumes, and the combination of audiovisual conditions. All conditions were repeated with and without background noise. Speech tasks included counting, sustained vowel phonation, an all-voiced sentence from the Consensus Auditory-Perceptual Evaluation of Voice, and the first sentence from the Rainbow Passage, randomly ordered. Perception outcome measures were participants' self-reported perceptions of their vocal loudness, vocal effort, and vocal comfort in speech. Production outcome measures were sound pressure level (SPL) and spectral moments (spectral mean and standard deviation in Hz, skewness, and kurtosis). Statistical analyses used self-reported vocal effort, vocal loudness, and vocal comfort in percent (0 = "not at all," 100 = extremely), SPL in dB, and spectral moments in Hz. The reference level was a baseline audiovisual deprivation condition. Results suggested (i) increased self-perceived vocal loudness and effort, and decreased comfort, with increasing room volume, speaker-to-listener distance, audiovisual input, and background noise, and (ii) increased SPL and fluctuations in spectral moments across conditions. Not only auditory, but also visual and audiovisual input influenced voice perception and production in ways that have not been previously documented. Findings contribute to the basic science understanding the role of visual, audiovisual and auditory input in voice perception and production, and also to models of voice training and therapy. The findings also set the foundation for the use of virtual reality in voice and speech training, as a potentially power solution to the generalization problem.

Preliminary Perceptual Findings of Singing After Flow Phonation Voice Exercises for Singers in Training

Goals of voice therapy and vocal pedagogy share similar principles and therefore, therapy approaches designed to improve the disordered voice may be equally effective when used to enhance healthy voice and vice versa. The purpose of this study was to investigate the effects of flow phonation voice exercises on vocal characteristics of students in undergraduate vocal music training programs and examine their potential use in vocal pedagogy. A total of 10 cis females were recruited and were randomized into two groups: an experimental group (group 1, n=6) receiving five sessions of flow phonation intervention across 5weeks; and a control group (group 2, n=4) that did not receive any direct intervention other than vocal hygiene education. Participants provided data pertaining to auditory perception, subjective respiratory measures, voice-related quality of life, and vocal fatigue before and after 5weeks. Flow phonation exercises consisted of cup bubble blowing, gargling, and stretch and flow. Wilcoxon signed ranks test was administered to compare outcomes across time points and between groups. Data indicate statistically significant changes in auditory perception of the singing voice, and voice-related quality of life for the group that received flow phonation exercises alone. No other measures showed statistical significance. Overall, this study indicates that the use of flow phonation voice exercises has the potential to improve voice instruction within the voice studio. While our target enrollments were not met to achieve optimal statistical power, our hypotheses were at least partially supported. In particular, positive intervention-related changes were observed in self-perceived voice handicap, and auditory perception of singing which were not observed in the control group.

Reinke’s Edema: New Insights into Voice Analysis, a Retrospective Study

Reinke's edema (RE) is a pathological condition involving increased volume of the vocal folds and resulting in significant impact on speech, fundamental frequency, and vocal range. Literature reports few studies which analyze vocal features according to the severity of RE. The aims of this study were to investigate the aerodynamics, acoustic characteristics, and sound spectrograms of a group of RE patients and to assess whether there was any correlation with their endoscopic grading. A total of 98 patients were included in the study, 49 patients with RE and 49 healthy volunteers (HV). Multidimensional Voice Program was used to perform objective voice assessment. Maximum phonation time (MPT) and Voice Handicap Index (VHI) questionnaire were collected. The spectrograms of the vowel /a/ and of the word /aiuole/, which contains the five Italian vowels, of each patient were analyzed according to the classification of Yanaghiara modified by Ricci Maccarini and De Colle. Laryngological assessment was used to record vocal folds morphology according to Yonekawa's classification. Univariate analysis was used to compare group outcomes. Bivariate analysis was used to compare endoscopic grading and voice analysis results. Univariate analysis of the HV and RE groups revealed statistically significant differences (P<0.05) for the following parameters: jitter%, shimmer%, harmonic-to-noise ratio (NHR), voice turbulence index (VTI), MPT, VHI except for soft phonation index. Spearman's rank correlation showed a positive correlation between vocal parameters such as jitter%, shimmer%, NHR, VTI, and RE gradings. A negative correlation was found between MPT and RE gradings. Bivariate analysis indicated a strong positive correlation between RE grading and the spectrogram classification performed both with the vowel / a / (Rho 0.86; P=0.0001) and with the word / aiuole / (Rho 0.81; P=0.0001). The present study demonstrates that patients with RE have different voice characteristics compared to HV. In particular, the voice analysis highlighted acoustic parameters that correlated to differing degrees of RE. In addition, spectrogram analysis should be considered for acoustic assessments before and after medical and surgical therapy and also in forensic medicine.

Trajectory of Voice Rehabilitation in Ortner’s Syndrome: A Case Report

Ortner’s syndrome is characterized with hoarseness of voice due to left recurrent laryngeal nerve palsy and is primarily caused by cardiovascular disease. Based on the concurrent impairment of both the heart and voice, it is also described as Cardio-Vocal syndrome. Hoarseness and breathiness, are the core voice features of Ortner’s syndrome, occurring in children and adults alike. Formal and customized vocal rehabilitation using symptomatic voice therapy approach can elicit remarkable voice improvement in such cases. In this case study, a 28 years old female with such cardiac pathology and voice symptoms is documented. Vocal rehabilitation was initiated, after medical intervention. Normal voice characteristic was achieved within nine sessions of voice therapy as evident in pre and post therapy comparison of acoustic and perceptual parameters. This finding is imperative to the narratives of such rare cases, as it emphasizes on the early intervention. The results suggest that management plays a vital role in restoration of vocal characteristics in cases where otherwise there could have been a permanent damage. There are a few literatures on the voice profile of persons with Ortner’s syndrome however, no study, to the best of our exhaustive search, has been reported on vocal rehabilitation profile on Ortner’s syndrome. The present study explores the trajectory of voice recovery in Ortner’s syndrome.

Threat vocalisations are acoustically similar between humans (Homo sapiens) and chimpanzees (Pan troglodytes)

ABSTRACT In behavioural contexts like fighting, eating, and playing, acoustically distinctive vocalisations are produced across many mammalian species. Such expressions may be conserved in evolution, pointing to the possibility of acoustic regularities in the vocalisations of phylogenetically related species. Here, we test this hypothesis by comparing the degree of acoustic similarity between human and chimpanzee vocalisations produced in 10 similar behavioural contexts. We use two complementary analysis methods: Pairwise acoustic distance measures and acoustic separability metrics based on unsupervised learning algorithms. Cross-context analysis revealed that acoustic features of vocalisations produced when threatening another individual were distinct from other types of vocalisations and highly similar across species. Using a multimethod approach, these findings demonstrate that human vocalisations produced when threatening another person are acoustically similar to chimpanzee vocalisations in the same situation as compared to other types of vocalisations, likely reflecting a phylogenetically ancient vocal signalling system.

Effects of vocal fold oscillation characteristics on the aerosol droplet production

Although a large number of aerosol droplets are known to be produced from the human larynx during vocalizations, it remains unclear how vocal fold oscillations are involved in the droplet production. In this study, we synthesized vocalizations using two types of silicone vocal fold models and investigated the effects of these model configurations on the droplet production mechanisms by measuring the particle concentrations when artificial mucus was injected into the artificial larynx. One model, which oscillates with complete glottal closure, produced louder sounds with droplets, whose diameter ranged primarily from 0.3 to 2μm. In contrast, the other model, which oscillates without vocal fold collision, produced smaller sounds with droplets having larger diameters. Additional observations using the laser sheets and high-speed imaging demonstrated that the liquid films were formed just above the vocal folds when a constant jet flow was generated in the model which does not exhibit complete glottal closure. These results describe how different oscillation characteristics of the vocal folds may cause differences in droplet concentration.

Vocal Characteristics across English-Northern Sotho Bilingual Speakers: A Comparative Study

Introduction: Bilinguals constitute a significant portion of speech-language pathologists’ (SLPs) caseloads. Insight into the cross-linguistic effect on voice is needed to guide SLPs to make linguistically appropriate observations when working with heterogenous populations. Method: Nineteen female English-Northern Sotho bilinguals performed three speech tasks (reading, picture description, and monologue) in each language. Acoustic analysis of mean fundamental frequency (f₀), intensity, and articulation rate was conducted with Praat. A panel of blinded listeners reached consensus after independently reviewing the recordings during perceptual analysis of voice quality, resonance, and glottal attack. Results: The following statistically significant differences were found across and within the languages: The mean f₀ was 204.61 Hz in the Northern Sotho picture description yet 196.50 Hz in the English picture description. The mean intensity of reading in Northern Sotho was 66.38 dB whereas the mean intensity of reading in English was 65.09 dB. Articulation rate was 3.78 syllables/s in English passage reading and 3.41 syllables/s in Northern Sotho passage reading. Within English, passage reading elicited a significantly quicker articulation rate than the picture description (3.34 syllables/s) and monologue (3.46 syllables/s). Within Northern Sotho, mean f₀ was 203.83 Hz in passage reading yet 191.11 Hz in the monologue. Perceptual voice quality, glottal attack, and resonance were comparable across languages. Conclusion: Relationships between languages spoken, task performance, and vocal characteristics were observed in English-Northern Sotho bilingual females. SLPs must consider the interaction of language, task performance, and vocal characteristics when working with bilingual clients.

Sounds Like There was No Sexual Orientation Discrimination? Attributions to Discrimination on the Basis of Auditory Gaydar

ABSTRACT Auditory gaydar happens when people’s heterosexuality is called into question by their vocal characteristics. Auditory gaydar has been shown to prompt discrimination against both women and men interviewing for leadership positions. Two experiments tested whether attributional ambiguity makes auditory gaydar discrimination difficult to detect in such contexts. Either heterosexual participants (Study 1, n = 161) or heterosexual and sexual minority participants (Study 2, n = 238) heard short clips of straight- vs. lesbian/gay-sounding speakers, described as unsuccessful applicants for leadership positions. Participants explained the speakers’ unsuccessful outcome in their own words and rated the likelihood that gender and sexual orientation discrimination caused that outcome. Attributions to gender discrimination were common whilst attributions to sexual prejudice were vanishingly rare. Women targets were rated more likely to have experienced gender discrimination, and lesbian/gay-sounding targets were rated more likely to have experienced sexual orientation discrimination by some participants (Study 1) or all participants (Study 2). We conclude that auditory gaydar may prompt discriminatory treatment in leadership hiring processes more readily than in prompts the recognition that discrimination on the basis of sexual orientation has occurred.

Multisensory interactions of face and vocal information during perception and memory in ventrolateral prefrontal cortex.

The ventral frontal lobe is a critical node in the circuit that underlies communication, a multisensory process where sensory features of faces and vocalizations come together. The neural basis of face and vocal integration is a topic of great importance since the integration of multiple sensory signals is essential for the decisions that govern our social interactions. Investigations have shown that the macaque ventrolateral prefrontal cortex (VLPFC), a proposed homologue of the human inferior frontal gyrus, is involved in the processing, integration and remembering of audiovisual signals. Single neurons in VLPFC encode and integrate species-specific faces and corresponding vocalizations. During working memory, VLPFC neurons maintain face and vocal information online and exhibit selective activity for face and vocal stimuli. Population analyses indicate that identity, a critical feature of social stimuli, is encoded by VLPFC neurons and dictates the structure of dynamic population activity in the VLPFC during the perception of vocalizations and their corresponding facial expressions. These studies suggest that VLPFC may play a primary role in integrating face and vocal stimuli with contextual information, in order to support decision making during social communication. This article is part of the theme issue 'Decision and control processes in multisensory perception'.

A Novel Artificial-Intelligence-Based Approach for Classification of Parkinson's Disease Using Complex and Large Vocal Features.

Parkinson's disease (PD) affects a large proportion of elderly people. Symptoms include tremors, slow movement, rigid muscles, and trouble speaking. With the aging of the developed world's population, this number is expected to rise. The early detection of PD and avoiding its severe consequences require a precise and efficient system. Our goal is to create an accurate AI model that can identify PD using human voices. We developed a transformer-based method for detecting PD by retrieving dysphonia measures from a subject's voice recording. It is uncommon to use a neural network (NN)-based solution for tabular vocal characteristics, but it has several advantages over a tree-based approach, including compatibility with continuous learning and the network's potential to be linked with an image/voice encoder for a more accurate multi modal solution, shifting SOTA approach from tree-based to a neural network (NN) is crucial for advancing research in multimodal solutions. Our method outperforms the state of the art (SOTA), namely Gradient-Boosted Decision Trees (GBDTs), by at least 1% AUC, and the precision and recall scores are also improved. We additionally offered an XgBoost-based feature-selection method and a fully connected NN layer technique for including continuous dysphonia measures, in addition to the solution network. We also discussed numerous important discoveries relating to our suggested solution and deep learning (DL) and its application to dysphonia measures, such as how a transformer-based network is more resilient to increased depth compared to a simple MLP network. The performance of the proposed approach and conventional machine learning techniques such as MLP, SVM, and Random Forest (RF) have also been compared. A detailed performance comparison matrix has been added to this article, along with the proposed solution's space and time complexity.

Prediction of mental effort derived from an automated vocal biomarker using machine learning in a large-scale remote sample.

Biomarkers of mental effort may help to identify subtle cognitive impairments in the absence of task performance deficits. Here, we aim to detect mental effort on a verbal task, using automated voice analysis and machine learning. Audio data from the digit span backwards task were recorded and scored with automated speech recognition using the online platform NeuroVocalixTM, yielding usable data from 2,764 healthy adults (1,022 male, 1,742 female; mean age 31.4 years). Acoustic features were aggregated across each trial and normalized within each subject. Cognitive load was dichotomized for each trial by categorizing trials at >0.6 of each participants' maximum span as "high load." Data were divided into training (60%), test (20%), and validate (20%) datasets, each containing different participants. Training and test data were used in model building and hyper-parameter tuning. Five classification models (Logistic Regression, Naive Bayes, Support Vector Machine, Random Forest, and Gradient Boosting) were trained to predict cognitive load ("high" vs. "low") based on acoustic features. Analyses were limited to correct responses. The model was evaluated using the validation dataset, across all span lengths and within the subset of trials with a four-digit span. Classifier discriminant power was examined with Receiver Operating Curve (ROC) analysis. Participants reached a mean span of 6.34 out of 8 items (SD = 1.38). The Gradient Boosting classifier provided the best performing model on test data (AUC = 0.98) and showed excellent discriminant power for cognitive load on the validation dataset, across all span lengths (AUC = 0.99), and for four-digit only utterances (AUC = 0.95). A sensitive biomarker of mental effort can be derived from vocal acoustic features in remotely administered verbal cognitive tests. The use-case of this biomarker for improving sensitivity of cognitive tests to subtle pathology now needs to be examined.

SocialBit: protocol for a prospective observational study to validate a wearable social sensor for stroke survivors with diverse neurological abilities

IntroductionSocial isolation has been found to be a significant risk factor for health outcomes, on par with traditional risk factors. This isolation is characterised by reduced social interactions, which can...

Species recognition and the divergences in the chemical and ultrasonic signals between two coexisting Rattus species.

The ability to recognize and differentiate between conspecifics and heterospecifics as well as their signals is critical for the coexistence of closely related species. In the genus Rattus, species are morphologically similar and multiple species often coexist. Here, we investigated the interspecific recognition and signal differentiation of two sympatric rat species, the brown rat (Rattus norvegicus, RN) and the Asian house rat (Rattus tanezumi, RT). In a two-way choice test, both RN and RT females showed a preference for conspecific male rats to heterospecific ones. RT females showed a significant preference for accessible urine of males of same species to those of other species, but not for the inaccessible urine. On the other hand, there were significant differences in the structural characteristics of the ultrasonic vocalization emitted by males of these two rat species. Sodium dodecyl sulphate‒polyacrylamide gel electrophoresis (SDS‒PAGE) and isoelectric focusing electrophoresis unveiled that major urinary proteins (MUPs) in voided urine were more highly expressed in RN males versus RT males. The interspecific differences of urinary volatile compounds were also discussed. In conclusion, female rats had the ability to distinguish between males of either species.

Repeated mild traumatic brain injury triggers pathology in asymptomatic C9ORF72 transgenic mice.

Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are fatal neurodegenerative diseases that represent ends of the spectrum of a single disease. The most common genetic cause of FTD and ALS is a hexanucleotide repeat expansion in the C9orf72 gene. Although epidemiological data suggest that traumatic brain injury (TBI) represents a risk factor for FTD and ALS, its role in exacerbating disease onset and course remains unclear. To explore the interplay between traumatic brain injury and genetic risk in the induction of FTD/ALS pathology we combined a mild repetitive traumatic brain injury paradigm with an established bacterial artificial chromosome transgenic C9orf72 (C9BAC) mouse model without an overt motor phenotype or neurodegeneration. We assessed 8-10 week-old littermate C9BACtg/tg (n = 21), C9BACtg/- (n = 20) and non-transgenic (n = 21) mice of both sexes for the presence of behavioural deficits and cerebral histopathology at 12 months after repetitive TBI. Repetitive TBI did not affect body weight gain, general neurological deficit severity, nor survival over the 12-month observation period and there was no difference in rotarod performance, object recognition, social interaction and acoustic characteristics of ultrasonic vocalizations of C9BAC mice subjected to repetitive TBI versus sham injury. However, we found that repetitive TBI increased the time to the return of the righting reflex, reduced grip force, altered sociability behaviours and attenuated ultrasonic call emissions during social interactions in C9BAC mice. Strikingly, we found that repetitive TBI caused widespread microglial activation and reduced neuronal density that was associated with loss of histological markers of axonal and synaptic integrity as well as profound neuronal transactive response DNA binding protein 43 kDa mislocalization in the cerebral cortex of C9BAC mice at 12 months; this was not observed in non-transgenic repetitive TBI and C9BAC sham mice. Our data indicate that repetitive TBI can be an environmental risk factor that is sufficient to trigger FTD/ALS-associated neuropathology and behavioural deficits, but not paralysis, in mice carrying a C9orf72 hexanucleotide repeat expansion.