CAPE TOWN – The search for the source of Table View’s mysterious humming noise in Cape Town has continued into the early hours, with residents, Nicholas Gotsell and councillor Sue van der Linde taking to the streets in an attempt to locate the elusive sound.

Gotsell and Van der Linde were out in the early hours of Thursday 10 September, after residents once again reported hearing the low-frequency hum during the early morning.

In a light-hearted video documenting the search, Gotsell joked: “Do you believe in aliens? Apparently they operate in the Table View area between three and five in the morning. Let’s go find them.”

The pair started their search around Bolt Avenue, an area with several factories and production lines, but found the area remarkably quiet.

“So we’re in the heart of this and it’s dead quiet,” Gotsell said.

They then moved towards Koeberg Road, where they again found no obvious source. A faint humming sound was eventually detected, but Gotsell said it appeared to be coming from the direction of the refinery and was accompanied by the sounds of birds and dogs.

“This hum from the refinery, which we can hear from Hopley Road, is not it,” he said.

The search continued to Appaloosa Dog Park, but the source remained elusive. By about 04:15, the mystery had still not been solved.

“We cannot find the noise. Not today,” Gotsell said. He and Van der Linde are now asking residents to provide more information about where and when they hear the sound, with residents encouraged to join Van der Linde’s WhatsApp group and share recordings and locations.

Residents put forward theories

The latest search has prompted further theories from residents about what could be behind the persistent noise.

One resident suggested that container ships anchored close to the coast could be responsible.

The resident said MSC container vessels had recently been anchored close to Dolphin Beach and claimed to have made audio recordings of the noise. While a ship’s main propulsion engine is switched off when anchored, the resident pointed out that auxiliary diesel generators continue operating to provide electricity.

According to the resident, the distance the sound travels and how loud it appears can depend on weather conditions, topography and wind direction.

Another resident offered a different theory, suggesting that machinery associated with illegal hydroponic growing could potentially be responsible for a persistent nighttime hum.

This remains an unverified theory and there is no evidence at this stage linking illegal activity to the Table View noise.

City investigation continues

The mystery comes as the City of Cape Town continues investigating complaints about the sound.

Van der Linde recently received an update from the City’s Noise Control Administration confirming that complaints had been received about noise reportedly heard in Table View and surrounding areas.

The City said the matter was being investigated under the Western Cape Noise Control Regulations, 2013.

It warned that identifying intermittent or unidentified noise sources can be difficult and may require repeated observations and technical monitoring.

The City also stressed that investigations are based on objective evidence, including officials’ observations and technical measurements.

“​​Audibility of a noise alone does not always constitute a contravention of the legislation,” the City said.

The investigation remains ongoing.

The City said seven officials are responsible for noise investigations across Cape Town and that the matter could not simply be expedited without affecting service delivery in other areas.

However, it said officials would continue pursuing reasonable lines of enquiry and use available resources to determine whether regulatory action is warranted.

Could sewer operations be responsible?

The latest developments follow a City noise alert issued on Wednesday 9 September, after residents again reported the low-frequency sound across areas including Table View, Bloubergstrand and Milnerton.

The City said its Water and Sanitation Directorate carries out essential wet-well cleaning at sewer pump stations, often between midnight and 04:00 when sewer flows are lower.

Specialised vacuum and jetting trucks used during this work can generate significant mechanical noise. The City has undertaken to investigate whether current Water and Sanitation operations could be linked to the reports.

Van der Linde has also asked the City to monitor pump stations in and around the area and compare maintenance and emergency-operation times with reports from residents.

So far, she said, she had not found a clear correlation.

Residents continue the hunt

For residents who have heard the hum repeatedly, sometimes for months or years, the latest investigation has renewed hopes that its source can eventually be identified.

Residents are being asked to record the exact time and location whenever they hear the sound and, where possible, make an audio recording.

For now, the source remains unknown, with possible explanations ranging from ships and industrial activity to sewer operations – while the early-morning search has at least ruled out one thing: the suspected “aliens” were nowhere to be found.

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