A method for operating a head-mounted display, HMD, device (120, 320, 420, 520) that includes a display (460, 560), comprising: automatically determining a position of the display (460, 560) relative to a line-of-sight, LOS, of a user that is wearing the HMD device (120, 320, 420, 520); and processing a change in operational modes of the HMD device (120, 320, 420, 520) based on the determined position of the display (460, 560), the operational modes including a first operational mode when the position of the display (460, 560) is determined to be within the LOS of the user, and a second operational mode when the position of the display (460, 560) is determined to be outside the LOS of the user, wherein operating the HMD device (120, 320, 420, 520) in the second operational mode includes: for a content to provide to the user being a notification comprising a visual element, determining a feature of the content; when the feature of the content is associated with a visual-optional condition, providing the user, via an electroacoustic transducer (332, 334, 336) included in the HMD device (120, 320, 420, 520), an audible indication of the visual element; and when the feature of the content is associated with a visual-only condition, providing the user, via the electroacoustic transducer, an audible indication of the visual-only condition, the audible indication of the visual-only condition being computer-generated speech providing a warning or a request, for the user to position the display (460, 560) within the LOS of the user for the HMD device (120, 320, 420, 520) to transition to the first operational mode and provide visually the content to the user via the display (460, 560) once the display (460, 560) is positioned within the LOS of the user. automatically determining a position of the display (460, 560) relative to a line-of-sight, LOS, of a user that is wearing the HMD device (120, 320, 420, 520); and processing a change in operational modes of the HMD device (120, 320, 420, 520) based on the determined position of the display (460, 560), the operational modes including a first operational mode when the position of the display (460, 560) is determined to be within the LOS of the user, and a second operational mode when the position of the display (460, 560) is determined to be outside the LOS of the user, wherein operating the HMD device (120, 320, 420, 520) in the second operational mode includes: for a content to provide to the user being a notification comprising a visual element, determining a feature of the content; when the feature of the content is associated with a visual-optional condition, providing the user, via an electroacoustic transducer (332, 334, 336) included in the HMD device (120, 320, 420, 520), an audible indication of the visual element; and when the feature of the content is associated with a visual-only condition, providing the user, via the electroacoustic transducer, an audible indication of the visual-only condition, the audible indication of the visual-only condition being computer-generated speech providing a warning or a request, for the user to position the display (460, 560) within the LOS of the user for the HMD device (120, 320, 420, 520) to transition to the first operational mode and provide visually the content to the user via the display (460, 560) once the display (460, 560) is positioned within the LOS of the user. for a content to provide to the user being a notification comprising a visual element, determining a feature of the content; when the feature of the content is associated with a visual-optional condition, providing the user, via an electroacoustic transducer (332, 334, 336) included in the HMD device (120, 320, 420, 520), an audible indication of the visual element; and when the feature of the content is associated with a visual-only condition, providing the user, via the electroacoustic transducer, an audible indication of the visual-only condition, the audible indication of the visual-only condition being computer-generated speech providing a warning or a request, for the user to position the display (460, 560) within the LOS of the user for the HMD device (120, 320, 420, 520) to transition to the first operational mode and provide visually the content to the user via the display (460, 560) once the display (460, 560) is positioned within the LOS of the user.