Towards Child-Appropriate Virtual Acoustic Environments: A Database of High-Resolution HRTF Measurements and 3D-Scans of Children

Abstract

Head-related transfer functions (HRTFs) play a significant role in modern acoustic experiment designs in the auralization of 3-dimensional virtual acoustic environments. This technique enables us to create close to real-life situations including room-acoustic effects, background noise and multiple sources in a controlled laboratory environment. While adult HRTF databases are widely available to the research community, datasets of children are not. To fill this gap, children aged 5–10 years old were recruited among 1st and 2nd year primary school children in Aachen, Germany. Their HRTFs were measured in the hemi-anechoic chamber with a 5-degree × 5-degree resolution. Special care was taken to reduce artifacts from motion during the measurements by means of fast measurement routines. To complement the HRTF measurements with the anthropometric data needed for individualization methods, a high-resolution 3D-scan of the head and upper torso of each participant was recorded. The HRTF measurement took around 3 min. The children’s head movement during that time was larger compared to adult participants in comparable experiments but was generally kept within 5 degrees of rotary and 1 cm of translatory motion. Adult participants only exhibit this range of motion in longer duration measurements. A comparison of the HRTF measurements to the KEMAR artificial head shows that it is not representative of an average child HRTF. Difference can be seen in both the spectrum and in the interaural time delay (ITD) with differences of 70 μs on average and a maximum difference of 138 μs. For both spectrum and ITD, the KEMAR more closely resembles the 95th percentile of range of children’s data. This warrants a closer look at using child specific HRTFs in the binaural presentation of virtual acoustic environments in the future.

Masked Speech Recognition by Normal-Hearing 6–13-Year-Olds in Conditions With and Without Interaural Difference Cues

“…As a side remark, the co-located and spatially separated conditions were implemented using generic head-related impulse responses measured on a KEMAR dummy-head, as also done in the LISN-N ( Cameron & Dillon, 2007 ). Braren and Fels (2021) recently published a database containing corresponding measurements made on 5–10-year-olds as well as on KEMAR. A comparison of their child and KEMAR data shows that low-frequency interaural time differences are similar in magnitude, whereas high-frequency monaural spectral cues are much more variable in 5–10-year-olds (see Figures 6–7 in Braren & Fels, 2021 ).…”

“… Braren and Fels (2021) recently published a database containing corresponding measurements made on 5–10-year-olds as well as on KEMAR. A comparison of their child and KEMAR data shows that low-frequency interaural time differences are similar in magnitude, whereas high-frequency monaural spectral cues are much more variable in 5–10-year-olds (see Figures 6–7 in Braren & Fels, 2021 ). Nevertheless, high-frequency interaural level differences appear similar in overall magnitude.…”

Music and voice interventions in the NICU: a novel adaptive personalized auditory care based on biophysical feedback

“…In a second step, a sound rendering environment will be deployed using dedicated headphones, implementing binaural sound. For that, the individual HRTFs will be collected from MRI acquisitions [29]).…”

Feasibility of Virtual Reality-Based Auditory Localization Training With Binaurally Recorded Auditory Stimuli for Patients With Single-Sided Deafness

“…As mentioned in the introduction, since the standard HRTF database does not incorporate individual variation in spectral cues, the benefits of individualized HRTF demonstrated in normal hearing subjects [12,13] are expected to be greater in patients with SSD. However, the generation of personal HRTFs based on individual measurement is highly time-consuming, technically difficult, and expensive [28]. Our method of binaural recording could easily capture the individualized spatial information in the head-centered position.…”