Understanding signal-to-noise ratio

Signal-to-noise ratio (SNR) compares the level of speech with background noise at the listener’s position. A positive SNR means the speech level is higher than the background noise level.

A more favourable SNR can support speech understanding. Listening also depends on reverberation, individual hearing and language needs, and the activity taking place. Managing noise and choosing suitable microphone and speaker arrangements can help improve listening conditions.

How distance affects classroom listening

As a listener moves further from the teacher, the direct speech signal becomes weaker. Background noise and reflected sound can then have a greater influence on what the listener hears.

The effect on speech understanding varies with room acoustics, seating position and individual needs. A classroom assessment can help identify suitable adjustments, such as seating changes, acoustic treatment, a SoundField system or personal remote microphones.

What research says about classroom SoundField

A 2022 review by Kiri Mealings found that SoundField amplification can benefit children’s listening and learning in primary schools. The review also highlighted the importance of students’ backgrounds, room reverberation, classroom layout and the type of learning activity.

These findings support considering SoundField as part of a classroom listening plan, with performance assessed in the actual room and for its intended users.

Putting evidence into practice

Classroom audio planning can include:

• Assessing background noise and reverberation

• Checking microphone position, speaker placement and volume settings

• Considering personal remote microphones, visual supports and other individual adjustments

• Gathering teacher and student feedback and checking performance after installation

A classroom SoundField system should work alongside suitable room acoustics and individual listening support.

Research reference: Mealings, K. (2022). A Review of the Effect of Classroom Sound-Field Amplification on Children in Primary School. American Journal of Audiology, 31(2), 470–486. Read the research abstract.

Plan for different ways of accessing information

Universal Design for Learning (UDL) encourages planning for learner differences from the outset. For classroom communication, this can mean combining spoken instructions with written key points, visual explanations, demonstrations and captioned media.

Choose options with students and teaching staff, and check whether the information is accessible in practice.

Respond to individual listening needs

Classroom-wide improvements may need to be combined with individual adjustments. These could include different seating, personal remote microphones, captioning or other support chosen for the person and activity.

Discuss listening concerns with the student, family and relevant school support staff. An individual assessment may help identify appropriate adjustments.

Review access across activities

Listening demands can change during group work, assemblies, outdoor lessons and movement between classrooms. Check how students will receive teacher and peer speech in each setting and how personal hearing technology will work with the classroom equipment.

Further reading: CAST Universal Design for Learning Guidelines.

Check compatibility before choosing technology

Wireless features vary between hearing devices and classroom audio systems. Confirm the exact models, software versions, connections and any required receivers or accessories before ordering.

Check the proposed setup for teacher instruction, student discussion and other activities where listening support is needed.

Help staff use the system consistently

Provide a demonstration and opportunities for staff to practise. Training should cover:

• Wearing and positioning the microphone

• Using mute, volume and audio-input controls

• Charging equipment and carrying out daily checks

• Reporting faults and arranging maintenance

Agree who will manage routine checks and provide support when equipment is moved or teaching arrangements change.

Review comfort and communication needs

Ask students and staff about comfortable listening levels, sudden sounds and situations they find difficult. Set audio levels for the room and activity, then review feedback after installation.

Manage background noise and reverberation alongside the amplified audio. Acoustic improvements, communication strategies or individual adjustments may also be needed.

Discuss your classroom listening needs with Hear Room

Hear Room supplies classroom audio equipment and provides assessment, system design, commissioning, training and support. We consider the room, teaching practices and students’ listening needs when recommending equipment and setup.

To discuss your classroom or building project, email info@hearroom.com.au or call 07 3387 0108.