This study shows that the turbulent velocities most strongly correlated with outer-scaled ($\delta$-scaled) wall-pressure fluctuations beneath a zero-pressure-gradient boundary layer reside within the logarithmic region. Even though contributions from the wake region are present, they are found to be statistically less dominant than those from the logarithmic region. The findings are based on bespoke measurements using an array of 63 microphones spanning $5\delta$ in the streamwise direction (where $\delta$ is the boundary layer thickness), which synchronously captures space-time $p_w$ data alongside streamwise velocity fluctuations $\left(u\right)$ from a single hotwire probe at the array's downstream end. The array is designed to spatially filter $p_w$ signals to uncover outer-scale contributions, by accurately resolving the large-scale portion of the frequency-wave-number $p_w$ spectrum while avoiding aliasing of small-scale energy. This design, and its effectiveness in anti-aliasing, is validated against previously published low-Reynolds-number simulation datasets of turbulent boundary layer flow. Present experiments span a friction Reynolds number range of $1400\lesssim {\mathrm{Re}}_{\tau }\lesssim 5200$, over which the large-scale energy in the boundary layer grows significantly. This growth is reflected in both the frequency-wave-number $p_w$ spectrum and the space-time $p_w$ correlations, both of which show scaling trends reflective of the large-scale pressure field convecting at an outer-scaled velocity of $0.75U_{\infty }$, where $U_{\infty }$ is the freestream velocity. The linear coherence between streamwise velocity and large-scale $p_w$ is directly quantified through space-time $p_w\text{–}u$ correlations, which show increasing magnitudes across the inner region with rising ${\mathrm{Re}}_{\tau }$. At the top of the logarithmic region, the correlation contours resemble outer-scaled coherent structures akin to large- and very-large-scale motions. A clear Reynolds number trend is also evident in the average convection velocities inferred from $p_w\text{–}u$ correlations, which increasingly deviate from the local mean velocity towards the outer-scaled convection velocity across the inner region. These insights provide a critical foundation for leveraging wall-pressure fluctuations in modeling and control of high-${\mathrm{Re}}_{\tau }$ boundary layers, where large-scale motions increasingly dominate the turbulence dynamics.

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• Boundary layers
• Structure & turbulence of boundary layers
• Turbulent boundary layers
• Coherent structures
• Hot-wire anemometry