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Since its inauguration in 2002, Esplanade Theatres on the Bay has captivated audiences with its distinctive twin shells, earning the moniker “The Durian” among locals. More than just a venue for performances, Esplanade embodies the spirit of creativity, innovation, and inclusivity, offering a diverse array of world-class productions and immersive experience for all.

 

From now to October 2025, Esplanade Theatres are undergoing upgrading works in phases, for their performance venues. One of the key components that Esplanade Theatres are looking to upgrade are their existing Infra-Red (IR) Systems catered for patrons who have hearing impairment. With that, Esplanade Theatres got in touch with the Top AV System Integrator in Southeast Asia, Electronics & Engineering Pte Ltd who introduced The Listening Lab to be part of the upgrading works to upgrade Esplanade Theatre’s existing IR System by proposing an FM System that is more robust.

 

The NUS School of Computing is proud to introduce their new facility, the 5-storey COM4 building, where student of NUS’ School of Computing can utilise for various uses from discussions, to learning and teaching labs. The School of Computing has decided to cater their facility to be as inclusive as possible which has accessibility, including Hearing Enhancement Systems to be implement within the rooms throughout the building.

 

Hearing Enhancement Systems or Induction loop systems have become an integral part of ensuring accessibility and inclusivity for individuals with hearing impairments. These systems use magnetic fields to transmit sound directly to hearing aids or cochlear implants, enabling users to hear clearly in public spaces, such as theatres, lecture halls, and conference rooms. However, to ensure optimal performance, it is crucial to understand two important concepts related to induction loop systems: vertical and adjacent crosstalk or Overspill. In this article, we will delve into these concepts and explore their significance in creating a seamless listening experience for all.

 

What is Vertical Overspill?

 

Vertical overspill refers to the dispersion of the magnetic field generated by an induction loop system above and below the intended coverage area. It occurs when the magnetic field extends beyond the desired boundaries, leading to signal leakage and potential interference with other induction loop systems that are located above and below. Vertical overspill can cause problems in multi-story buildings or venues with multiple floors or rooms situated above and below each other. To mitigate vertical overspill, the installation of induction loop systems should involve careful consideration of the venue's structure and acoustics and in this case, the induction loops can be found above the false ceiling.
 

 

Factors affecting Vertical Overspill

 

Factors such as the height of the loop, the presence of metal structures or obstacles, and the layout of adjacent rooms or floors can impact the extent of vertical overspill. By using appropriate loop designs, like a low spill multiloop, it is possible to limit the magnetic field's vertical dispersion, focusing the signal within the desired listening area and minimizing interference with other spaces.

 

Challenges in installing Induction Loops in Ceilings

 

The standard location in installing Induction Loops would be either on or in the floor. However, there are special circumstances in which resorting to installations of induction loops in the ceilings would be a requirement to overcome the vertical overspilling of signals between rooms that are above and below each other.

 

The challenges faced when installing of ceiling loops are;

1. Height of ceiling – during installation and future troubleshooting if required, the induction loops will be at heights of at least 2.5 meters which requires ladder access.
2. Access and Space Constraints – Dependent on the overall height of the room, access to ceilings would require the usage of ladders and following that, when working with false ceilings, the presence of the aluminum grids reduce the accessibility and space that installers have.
3. Material of Ceiling – metal grids of false ceilings can have an impact to the overall performance of the induction loop due to Metal Loss, hence proper planning is required for an effective effect.
4. Presence of other services in ceilings – other services will also be housed in the space above the false ceiling, hence, proper coordination between contractors is crucial to ensure that there is sufficient space to install the induction loop systems.

 

Achieving IEC 60188-4 Compliance for Induction Loops in Ceilings

 

In NUS COM4’s context, the induction loops are installed at 3.3 meters from the floor which is quite a distance that requires a higher rating loop driver to be able to generate the signal down to the listening height which is at seated position. On top of that, the performance of the induction loop is further hindered by Metal Loss that is due to the aluminium grids that hold up the ceiling boards.

 

To overcome these challenges, the highest rated amplifiers were proposed to check the requirements to comply to the IEC 60118-4 standards for induction loops that were installed in the ceilings.

 

What is Adjacent Overspill?

 

Adjacent overspill refers to the spreading of the magnetic field beyond the intended coverage area horizontally. It occurs when the magnetic field extends into neighbouring areas, potentially causing overlapping signals and reducing clarity. Adjacent overspill is particularly relevant in environments where multiple induction loop systems are installed side by side or in close proximity.

 

To address adjacent overspill, proper planning and design are crucial. The spacing between adjacent induction loop systems should be carefully determined to avoid interference. Additionally, advanced signal processing techniques can be employed to reduce crosstalk and enhance the separation of adjacent systems.

 

Importance of Minimizing Overspill

 

Minimizing both vertical and adjacent overspill is vital to ensure a high-quality listening experience for individuals using hearing aids or cochlear implants. Excessive overspill can lead to sound distortion, reduced speech intelligibility, and confusion, thereby defeating the purpose of installing an induction loop system. By understanding and addressing these issues during the system's design and installation phase, venue owners and specialists can maximize the system's effectiveness and provide equal access to audio information for all individuals.

 

Conclusion

 

Vertical and adjacent overspill are crucial considerations when implementing induction loop systems. To achieve optimal performance and user satisfaction, it is essential to carefully design and install the system while taking into account factors such as building structure, room layout, and neighbouring systems. By minimizing overspill through appropriate loop design, spacing, and signal processing techniques, venues can provide seamless access to audio information for individuals with hearing impairments, promoting inclusivity and enhancing the overall experience for all attendees.

In today's world, accessibility and inclusivity are paramount considerations across various domains, including public spaces, performances, and events. One crucial aspect of inclusivity involves ensuring that individuals with hearing impairments can fully participate and enjoy these experiences.

 

To address this need, induction loop systems have emerged as powerful tools, providing direct sound transmission to hearing aids and cochlear implants, bypassing background noise and delivering clear audio to the listener.

 

While induction loops have revolutionised accessibility, a particular challenge arises when these systems are installed in adjacent rooms or spaces. This challenge is known as the overspilling effect, where the magnetic field generated by an induction loop extends beyond its intended coverage area, potentially leading to audio leakage and compromised listening experiences. Understanding and mitigating the overspilling effect is vital to creating optimal audio environments for individuals with hearing impairments.

 

This study delves into the complexities of the overspilling effect in induction loop systems. We explore the factors influencing its occurrence, such as proximity, loop design, and loop amplification. Furthermore, we uncover strategies professionals employ to minimise the impact of overspilling, ensuring that individuals with hearing impairments can enjoy clear and private audio experiences in adjacent rooms or spaces.

 

By shedding light on the overspilling effect and sharing insights into its mitigation, we aim to foster greater awareness and understanding of this challenge. Join us on this journey as we navigate the intricacies of induction loop systems, and discover how professionals are working towards creating inclusive environments that prioritise accessibility for all individuals, regardless of their hearing abilities.

 

Renovating Shaw Theatres Balestier

 

 

Shaw Theatres Balestier opened its doors on 30th March 2023 after having undergone renovations for a design revamp since August 2019. It houses 11 theatre halls, making it the cinema with the most halls in a single location in Singapore. Six of the 11 halls are regular, while 4 Premium Lumiere Halls are located on the same level, and 1 Dreamers Hall is on one lower level.

 

 

Adjacent Cinema Halls on The Same Level

Halls 1 through 6 and Lumiere Halls 1 through 4 are located on the same level and are adjacent. Implementing the Induction Loop Systems in every hall poses a challenge due to Signal Interference or the Overspilling Effect.

 

Induction or hearing loops are vital in enhancing

Accessibility for individuals with hearing impairments. These systems utilise electromagnetic fields to transmit sound directly to hearing aids and cochlear implants, bypassing background noise and delivering clear audio to the listener.

 

While induction loops are commonly used in various public spaces, such as theatres, lecture halls, and places of worship, their effectiveness can be impacted by the overspilling effect when installed in adjacent rooms.

 

Understanding Overspilling

Overspilling occurs when the magnetic field generated by an induction loop system extends beyond its intended coverage area. This spillage can cause audio leakage from its intended location, potentially resulting in a breach of privacy or a degraded listening experience for individuals using hearing aids or cochlear implants equipped with telecoils (T-coils). In scenarios where multiple induction loops are installed in adjacent rooms or spaces, the overspilling effect can pose a significant challenge.

 

Factors Influencing the Overspilling Effect

 

1. Proximity: The distance between induction loop systems in neighbouring rooms affects the extent of magnetic field overlap. The closer the loops are, the greater the likelihood of overspilling.
2. Loop Design: The physical layout and design of the induction loops, including their shape, size, and orientation, can influence the reach of the magnetic field. Irregularly shaped rooms or areas with architectural barriers may worsen the overspilling effect.
3. Loop Amplification: The amplification level of the induction loop system impacts the strength of the magnetic field and, consequently, the overspilling effect. Higher amplification settings may lead to a more significant overspill.

 

Ways to Minimise the Overspilling Effect

While eliminating the overspilling effect may be challenging, there are several strategies that can help minimise its impact and maintain optimal accessibility.

 

1. Proper Loop Installation: Professional installation by specialists is crucial to ensure that induction loops are correctly positioned and calibrated. This includes considering the location and orientation of adjacent rooms to minimise overspill.
2. Loop Design Considerations: Architects and designers should collaborate with induction loop specialists during the planning phase of building projects to optimise loop design. This involves evaluating the physical characteristics of adjacent rooms and incorporating appropriate loop configurations to minimise overspill.
3. Loop Amplification Adjustment: Properly adjust the amplification level of the induction loop system to minimise overspill. Fine-tuning the amplification settings ensures the magnetic field is strong enough to provide sufficient coverage within the intended space without unnecessarily extending into adjacent areas.

 

As technology advances, new solutions for overcoming the overspilling effect are being developed. For example, some companies are developing induction loop systems that use directional microphones to direct the sound waves in a specific direction. This can help to reduce the amount of overspilling that occurs in adjacent rooms or spaces.

 

How We Overcame the Overspilling Effect Between Rooms

 

Loop Type Used: Low Spill Multiloop

 

To contain the signal from spilling not far from the loop boundary. Usually used to prevent the magnetic field generated by the loop from causing interference with the adjacent room.

 

To overcome the Overspilling Effect, we utilised a Low Spill Multiloop with a C7-2 Amplifier in tandem for every theatre hall to allow us to make precise minute adjustments to meet the IEC 60118-4 standards and to ensure that the overspilling effect between adjacent rooms is as low as possible.

 

Wheelchair Bay Area for Audiences with Hearing Aids

 

 

We focused on the wheelchair bay area, which has dedicated coverage for Wheelchair users who also happen to be wearing hearing aids. This ensures that comprehensive coverage is equal for standard seats and accessibility area seats.

 

 

 

 

Induction loops have significantly enhanced accessibility for individuals with hearing impairments, allowing them to enjoy public spaces, performances, and events with greater clarity and inclusivity. However, the overspilling effect on induction loops between adjacent rooms can challenge achieving optimal audio quality.

 

Conclusion

 

The overspilling effect in induction loop systems presents a significant challenge to achieving optimal audio quality and privacy in adjacent rooms or spaces. Factors such as proximity, loop design, and loop amplification influence the extent of the overspilling effect, requiring careful consideration during the installation and design phases.

 

However, strategic approaches and collaboration between professionals in the field can minimise the impact of overspilling and create inclusive environments for individuals with hearing impairments. Proper loop installation, design considerations, and fine-tuning loop amplification levels are crucial in reducing the overspilling effect and ensuring precise audio delivery to those relying on hearing aids or cochlear implants.

 

As technology advances, the accessibility landscape evolves, and solutions for overcoming the overspilling effect become more refined. Organisations like Listening Lab are at the forefront of providing hearing enhancement systems and services that fully empower individuals with hearing impairments to engage in various auditory experiences.

AWWA School is a specialized institution that educates children between the ages of 7 and 18 with multiple disabilities and autism. The school caters specialized education with multiple disabilities and autism to grow the potential for independence and improve the quality of life of students with special needs.

 

Located at 50 Bedok Reservoir Crescent, AWWA School at Bedok is a focal point serving children with autism. The school also delves into collaboration opportunities with their stakeholders to expose the students to the various platforms in the community, whereby they could develop, adapt and establish the skills they have acquired.

 

Multi-Purpose Hall

One of the key features of the school is its Multi-Purpose Hall (MPH), which is designed to accommodate different activities and events. However, implementing a hearing enhancement solution in the MPH proved challenging due to the high metal loss associated with the metal flooring.

Before installation, it is essential to understand the type of flooring used to help us develop a solution for the construction needs. The type of flooring used in AWWA School’s MPH is metal flooring.

 

Our biggest challenge was to overcome the high level of Metal Loss while implementing Flat Copper Tape to provide the electromagnetic field as part of the Hearing Enhancement Solution.

 

What is Metal Loss?

• The presence of metals near a loop will result in the signals being “bounced” back, resulting in a cancellation of the loop signal to a certain degree, affecting the Hearing Aid user with the Telecoil function.
• Common Metals found in installation sites would be:
  • Rebars or wire mesh in concrete floor/walls.
  • Metal reinforcement in walls or ceilings.
  • Overhead metal support structures.
• Metal loss results in a loss of high frequencies which causes the sound quality to be muffled.

When metal objects are present near a loop, signals are bounced back, causing some cancellation of the loop signal. Rebars or wire mesh in concrete floors and walls, metal reinforcement in walls or ceilings, and overhead metal support structures are all common metals in installation sites. Metal loss causes a loss of high frequencies, resulting in muffled sound quality.

 

Metal Loss Test

Why is Metal Loss Test required before installation?

• Crucial to carry out Metal Loss Test, especially when there is a significant metal content in the construction.
• To ensure that customers do not have to over-invest in a costly loop driver when it is unnecessary.
• To have a guaranteed preliminary result, the designed loop system with the necessary factors will perform within expectations. Flat Copper Tape will be implemented on top of the Metal Flooring of AWWA School’s MPH.

To ensure that the school will not over-invest in a costly loop driver, a Metal Loss Test is required before installation. This test is essential when the construction has significant metal content. The designed loop system with the essential factors can perform within expectations by conducting this test.

 

 

Type of Loop: Low Spill Multiloop

 

To contain the signal spill not far from the loop boundary. Usually used to prevent the magnetic field generated by the loop from causing interference with electrical equipment like electric guitars and dynamic microphones around the stage area.

 

Challenges faced: High Metal Loss

 

Metal flooring of the MPH will result in a muffled or dull audio quality for Hearing Aid users.

 

Solution

 

To overcome this, the installation team used two sets of C14-2Ns amplifiers, which is a higher capacity driver that allowed the driver to compensate for Metal Loss and achieve audio quality and clarity on par with or exceeding the IEC 60118-4 standards, also known as the International Performance standard for induction loop systems.