Read the passage below and choose one correct answer for each question.

Approximately one in two thousand people in Viet Nam has a significant hearing loss. Students who have been deafened in early childhood can be very different to students who have lost hearing later in life in terms of educational disadvantage. For example, their range of vocabulary may be limited, which in turn may affect their level of English literacy. Deaf and hard of hearing students can sometimes prefer visual learning strategies. This can be a challenge in an environment where much essential information is delivered exclusively by word of mouth. Students with a hearing loss may need to use assistive technology to participate in class. This assistive technology can be the laptop where software such as Skype can be used to deliver interpreters or captioning. For some, it will be in the form of listening devices. For others, it will be a combination of technology that includes both listening devices and computer based software. The impact of hearing loss can cause delays in receiving learning material. Students who need information transcribed from tape must sometimes wait for a significant period of time for this to happen. This needs to be considered in terms of developing suitable timelines for the completion of work for each student. Students with hearing loss may appear isolated in the learning environment. The possibility for social contact and interaction with other students is often limited, and this isolation or separateness may have an impact on learning. Participation and interaction in tutorials may be limited.  Students who cannot hear the flow and nuances of rapid verbal exchange will be at a disadvantage.

Question: Learning environment can have negative impact on deaf students when ______ .