Ocean Acoustics & Biomedical Ultrasound

Learning Outcomes

Disciplinary Specific Learning Outcomes

Having successfully completed this module you will be able to:

• Read, understand and interpret the literature relating to underwater acoustics and biomedical ultrasonics.
• Describe certain key discoveries and characteristics of underwater acoustics, nonlinear propagation and biomedical ultrasonics.

Propagation of sound in the ocean:

Plane wave equation, sound speed dependencies, sound speed profiles in the ocean.

Oceanic ray bending

Huygen’s principle, reflection of sound waves, transmission loss, bottom reflections

Oceanic noise

Sources of noise (Knudsen and Wenz spectra), rain, breaking, bubbles.

Sonar Equations

Classes of sonar systems. Prototypical sonar system. Passive and active sonar equations definition of terms. Reverberation.

Propagation modelling

Ray tracing models and normal modes.

Bioacoustics

Sound sensing and production in cetaceans (whales and dolphins). The role of acoustics in conservation of these animals. Analysis of echolocation capabilities of dolphins.

Non-linear acoustics

The propagation of finite amplitude waveforms; Acoustics streaming; Self-interaction, parametric and stimulated scattering effects in liquids.

Biomedical Ultrasound

Measurement; Clinical ultrasound (diagnosis and therapy); Mechanisms of biohazard (Hyperthermia, Cavitation).

Teaching methods include

3 lectures a week. Revision classes which go through past papers.

Students join the course with widely varying experience (it not being uncommon to find, in addition to the Master’s students from MSc Sound and Vibration Studies, the audience including MSc Ship Science, undergraduates, and members of biomedical and oceanography departments who sit in for certain lectures. There is also a wide range of language skills, and past experience of learning methods, in the audience. To approach this mix the style of teaching uses much discussion during lectures, with free questioning both ways, between lecturer and audience (though class being invited to think, rather than individuals being asked questions).

Learning activities include

The lecture style includes much discussion and exploration of ideas, to foster cognitive and reasoning skills, and to develop a logic approach to the topic. Past papers sheets are gone through with students on a tutorial basis in order to practise their analytical skills and these are backed up with interactive tutorial sessions. A lab class will be held and formative feedback will be given on the lab report. Students are encouraged to do past paper questions in their own time which will be marked if completed and feedback given. Students are encouraged to read supporting texts and a booklist is provided.

Formative

This is how we’ll give you feedback as you are learning. It is not a formal test or exam.

Laboratory Report

• Assessment Type: Formative
• Feedback:
• Final Assessment: No
• Group Work: No

Summative

This is how we’ll formally assess what you have learned in this module.

Referral

This is how we’ll assess you if you don’t meet the criteria to pass this module.

Repeat

An internal repeat is where you take all of your modules again, including any you passed. An external repeat is where you only re-take the modules you failed.